English test

Hi don't have answer key for this test. Could you help me?Correct answer is B or C?
If C can you explay why? This sentense "I’ll sleep for a while. " Who go sleep father or son who came to home?

Perhaps B?

1. On coming home from abroad the writer’s son

A. did not recognize his father. B. immediately went to bed. C. was so tired that he couldn’t sleep.

My fifteen-year-old son has just returned from abroad with a dozen rolls of exposed film and a hundred dollars in uncashed traveller’s cheques, and is asleep at the moment, drifting westward toward Central Time. Last night he slept in Paris, France, and the twenty nights before that in various beds in England and Scotland, but evidently he postponed as much sleep as he could. When he walked half-blindly in and we embraced, and he said he’d missed home, his electrical system suddenly switched off, and he headed half-unconscious for the bedroom. I don’t think I’ll sleep for a while. This household has been running a low fever since weeks before the trip began. It was his first trip overseas, so we pressed travel books on him, and a tape cassette of useful French phrases; advised him on clothing and other things. At the luggage store where we went to buy him a suitcase, he looked at a few suitcases and headed for the duffels and rucksacks. He said that suitcases were more for old people.