Apparently I ' m very allergic to cats . Did n't know that exactly until just these past two weeks . I fell asleep on the couch in the living room two weekends ago and had terrible sinus reactions . But here 's the rub .

Options are:
-- The cat had peed on the couch to try to mark it 's territory and this is what the speaker was allergic to.
-- The cat hair is very prevalent on furniture in the speaker 's house , and the couch is one example.
-- None of the above choices ..
-- The cat was confused at the fact of them sleeping on the couch and proceeded to scratch them.
Q: Why did falling asleep on the couch and becoming ill lead the speaker to realize they must be allergic to cats ?
The cat hair is very prevalent on furniture in the speaker 's house , and the couch is one example