How to delete Full Size options from post Add Media?

function remove_extra_image_sizes() {
    foreach ( get_intermediate_image_sizes() as $size ) {
        if ( in_array( $size, array( 'full' ) ) ) {
            remove_image_size( $size );
        }
    }
}
add_action('init', 'remove_extra_image_sizes');

Ref: remove_image_size() function

I think this will help you.