Which constant can you set in wp-config.php to limit the allowed memory for WordPress?

You can overwrite the siteurl option in wp-config.php with:

What does the line do? add_filter('show_admin_bar', '__return_false');

The function you use to access a WordPress site option is:

Which function do you use to sanitize a generic text field for saving in the database?

What is the proper order of parameters that get_the_post_thumbnail() accepts?

What does the line do? add_filter('show_admin_bar', '__return_false');

Which constant can you set in wp-config.php to limit the allowed memory for WordPress?