We started pitching the highest camp that has ever been made. Everything took five times as long as it would have taken in a place where there was enough air to breathe, but at last we got the, tent up and when we crawled in, it was not too bad. There was only a light wind, and inside it was not too cold for us to take off our gloves. At night most climbers take off their boots, but I prefer to keep them on. Hillary, on the other hand, took his off and laid them next to his sleeping bag.
They crawled into the tent because

Options

A. they must have been too tired to work
B. the entrance to the tent must have been low
C. they had heavy loads on their back
D. they wanted to hide from enemies

Answer

B