My friend Matt and I arrived at the Activity Centre on Friday evening. The accommodation wasn‘t wonderful, but we had everything we needed (beds, blankets, food ), and we were pleased to be out of the city and in the fresh air.

　　On Saturday morning we met the other ten members of our group. Cameron had come along with two friends, Kevin and Simon, while sisters Carole and Lynn had come with Amanda. There were some other members I didn‘t know. We had come from different places and none of us knew the area.

　　We knew we were going to spend the weekend outdoors, but none of us was sure exactly how. Half of us spent the morning caving while the others went rock-climbing and then we changed at lunchtime. Matt and I went to the caves （岩洞） first. Climbing out was harder than going in, but after a good deal of pushing, we were out at last.  Though we were covered with mud, we were pleased and excited by what we‘d done.

　　This passage mainly talks about ______________。

　　A. the writer‘s friends at the Activity Center B. the writer’s experience at the Activity Center

　　C. outdoor sports at the Activity Center D。 how to go rock-climbing and caving