It really depends on the situation. In most cases it's because you've emotionally attached yourself to a person and/or opened up to them. It also depends on the reason for the breakup. If you feel as though the relationship shouldn't have ended and you're still in love and/or still happy with that person you may question why they didn't want you, putting faults on yourself and making you look at yourself differently which can cause symptoms of depression or anxiety. Etc.
Chocolate is so good to eat
It is addicting because it’s sweet
I always think of it whenever I sleep
I like it whenever I want a good treat
The rhyming words at the end are memorable
Answer:
I believe being sick with the flu would be (c) a biological stress.