trying to save multiple select fields using update_options

Displaying a list of all pages in a select field. I want multiple pages to be able to be selected. I have been reading and reading, but still don’t seem to get how this works.

I can get the selected fields to echo out, but they don’t seem to be saving, i.e. when page is reloaded the selections are gone.

the fields:

<select id="exclude_page_from_cookies" name="exclude_page_from_cookies[]" multiple="multiple">
			<?php

			$pages = get_pages();
			foreach ( $pages as $page ) {
				$title = $page->post_title;
				$id    = $page->id;
				?>

				<option id="<?php echo $id; ?>" value="<?php echo $title ?>" <?php selected( $title ); ?> >
					<?php echo $title;?>
				</option>
			<?php
			}
			?>
		</select>

The save

if ( isset( $_POST['exclude_page_from_cookies'] ) ) {
			foreach( $_POST['exclude_page_from_cookies'] as $exclude_page ) {
				echo $exclude_page;
				update_option( 'exclude_page_from_cookies', $exclude_page ) ;
			}
		}

Thank you all in advance.