20. I thought about those small bits of self-confidence that were so painstakingly built in boyhood, and how they were being crushed at the counter.

A、I thought about a boy could be so shy and felt so much pain as he grew up and why he was feeling even more afraid to talk at the counter.;
B、I thought the young student must feel painful because he was destroying his self-confidence at the counter.;
C、I thought the young student was very self-confident that he did not want to did the talking at the counter.;
D、I thought about how the young students had gradually managed to build his self-confidence as a boy and how it was now being destroyed at the counter.