Registration drop down doesn’t prevent trolls

Sorry – from your original description it sounded like what you wanted was a required field. But here it seems like what you actually want/need is the equivalent of a “honey pot,” which is a field that if completed would indicate that a bot was completing the form and thus prevents a user from being created.

One simple solution is to get the WP-Members Security plugin. This extension has a number of additional features for the core plugin including a simple setting to create/add a honey pot field to the registration form.

Alternatively, I do have a tutorial article that is part of the premium support site that describes how to set up a honey pot for the registration form.
https://rocketgeek.com/filter-hooks/fighting-registration-spam-with-a-honey-pot/
https://rocketgeek.com/plugins/wp-members/support-options/

A honey pot, like any other form validation, is going to be hooked to wpmem_pre_register_data since that is the action that comes after automatic validation but before the user is created – in other words, this is where you stop the process if necessary.

Regarding your question about select field data:

The selection shows up as 1, 2 or 3 and not the state.

The values are entirely up to you when you create the field. Select/dropdown values (and other certain field types) are set as “display value|saved value” pairs where “display value” specifically means what shows to the user in the drop down selector and “saved value” is how that value is saved in the db. If you want “Maine” to be both the display and saved value, make your values like “Maine|Maine” not “Maine|one”.
For more information on how to set these up see: https://rocketgeek.com/plugins/wp-members/docs/registration/choosing-fields/

How can registration be limited to those living in Maine, NH or Mass? A honey pot will catch bots but not people living in other sates / countries.

Does WP Members have a way to exclude countries or am I thin king of another plugin?

The Pro Bundle form has an “Apply Coupon Code” field. Where are coupons available?

How can registration be limited to those living in Maine, NH or Mass?

Now that *would* be something that you’d use a required field for. OR, if it’s not set as a required field and left empty, use the wpmem_pre_register_data action to apply custom validation indicating they have to choose one of those states.

In my opinion, there’s not a perfect process without human intervention. You could restrict by IP address but what if a user’s IP is not perfectly related to their actual location? For example, I’m in a rural location and my IP address actually shows my location as being in the next county since that’s where the provider is located. What if that crosses a state line (which in my case, it certainly could since the county after that is in the next state)? Then there’s the certainty that given a selection, some people will lie.

The best possibility is to use a honey pot to restrict spam registrations, and use a required field for user to identify their location. You could regularly audit your other results (OR, use moderated registration that requires admin approval – and verify based on that information). It all depends on the individual situation.

The Pro Bundle form has an “Apply Coupon Code” field. Where are coupons available?

That’s just part of the shopping cart for use if I run a promotion. Most often, it’s used if I need to apply a discount to a specific user for a specific reason (i.e. if someone purchased a couple of individual items but then wanted to upgrade to the Pro Bundle – in those cases I usually give them a prorated price.)