This question has options. Answer the question about text:

Woke up at 3:30 am , could n't get back to sleep . It sucks . Two days ago I was still drowsy and sleeping all the time . I still want to sleep all the time , but it is not happening .

What may be the reason I can not go to sleep ?
OPT:
(A). I have to work nights ,;
(B). I have insomnia .;
(C). I have to study .;
(D). None of the above choices .;
(B).