if you are using a self-hosted site based on WordPress.org, please post your question in your theme's support section at http://wordpress.org/support/theme/adelle/
if your site is with WordPress.com, please post in http://en.forums.wordpress.com/
http://en.support.wordpress.com/com-vs-org/
[continued at https://wordpress.org/support/topic/no-mobile-option-under-appearance-urgent?replies=1 ]