请教GWD18-29,多谢

Q29:

The contractor and the engineer agree on the cause of the bridge failure, but both blame the other.

1. both blame the other

2. each blames the other

3. each blame the other person

4. both are blaming the other

5. each blames one another

答案是B, 我选择的是E, one another 的意思是另一个人，彼此，用在这句话正合适阿，不过也没觉得B有什么问题。