M: Would you please tell me about your best holiday, Nancy? W: Well, it was my trip in Nepal. We went there 10 years ago, doing some walking in the mountains. M: How long did you stay there? W: 20 days. M: 20 days! That's a long time. How far did you walk every day? W: Perhaps 15 kilometers. You have to climb up and down a lot every day. M: So, it was very hard. W: Yes, very hard. Sometimes, it's difficult to walk in the mountains where the air is very thin, and you have a lot of problems when breathing. M: What kind of equipment did you take? W: Not much. Only a bag, a sleeping bag and some warm clothing. We carried all the things by ourselves. M: And how was the food? W: There was rice and some vegetables, normally no meat. But it was good. M: What was the best thing about the trip? W: The walking and the exercise. I hate sitting in the sun and like to be out in the countryside. The air is very clean and it's very quiet. Nepal is a good place. You must go!, Question: What problem did they have? (A) They didn't have modern equipment. (B) There wasn't enough oxygen sometimes. (C) They couldn't walk freely in the mountains.
(B) There wasn't enough oxygen sometimes.