At Eton the boys stand in a cluster and lift their hats when their names are called.哪个译文更为恰切？

At Eton the boys stand in a cluster and lift their hats when their names are called.哪个译文更为恰切？
A.在伊顿，学生们站在一起，当他们的名字被叫到的时候，就举举帽子。
B.在伊顿，学生们站在一起，叫到名字就举举帽子。
正确答案：在伊顿，学生们站在一起，叫到名字就举举帽子。