Which sentence uses the word insomnia incorrectly?

a.
ralph’s teacher told him that insomnia was not a legitimate excuse for his project being two days late.
b.
at the banquet, every employee received a sweatshirt with the company’s insomnia on it.
c.
the only negative side effect of the medication i am taking is that it causes insomnia some nights.

Tobias wolff most likely named his short story "mortals" because the story explores the theme of people coming to terms with the idea that one day they too will die. wanting to find out what their loved ones really think of them. achieving immortalit by being "big people" while they are alive. hoping that they will have accomplished something before they die.