Learned the differences between single-agent problem and multi-agent problem, select a correct one form following descriptions. 学习了单智能体问题和多智能体问题之间的区别后，从如下描述中选择正确的答案。

A、Both of multi-effector problem and multi-body problem is a single-agent problem. 多效用器和多躯体这两者都是单智能体问题。

B、Both of multi-effector problem and multi-body problem is a multi-agent problem. 多效用器和多躯体这两者都是多智能体问题。

C、Multi-effector problem is a single-agent problem, but multi-body problem is not. 多效用器是单智能体问题，而多躯体是多智能体问题。

D、Multi-body problem is a multi-agent problem, but multi- effector problem is not. 多躯体是单智能体问题，而多效用器是多智能体问题。