Setting for failed fonts stated on GTMetrix

Hi,

I tested my site on GTMatrix and noticed fontawesome fonts are failing to load causing some page speed increase. These fonts are coming from my theme and an ajax plugin. My minify is switched on, what I would like to know is which setting is the appropriate setting in Minify that I am suppose to set:

Choose how to include Font Awesome (only available if it has ‘font-awesome’ in the url):

Inherit from the CSS settings
Inline the Font Awesome CSS file
Asynchronously load the Font Awesome CSS file
Asynchronously load the Font Awesome stylesheet using JavaScript

Much appreciated. Thanks