What is the underlying text structure of this excerpt?

Depression is a serious medical illness that involves the brain. It's more than just a feeling of being down in the dumps or blue for a few days. There are a variety of
causes, including genetic,
environmental, psychological, and biochemical factors. Depression usually starts between
the ages of 15 and 30 and is much more common in women than in men. There are effective treatments for depression, including antidepressants and talk therapy. Most people do best by using both.

Questions:

A) Description

B) if-then

C) compare and contrast

D) chronological sequence