I'm afraid Mr.lee?get to work on time ,he is in a traffic jam nowA can't B shouldn't C mustn't D needn't

I'm afraid Mr.lee?get to work on time ,he is in a traffic jam now
A can't B shouldn't C mustn't D needn't

A.
根据这句话的意思啊.
这句话：我担心李先生不能按时工作.其他意思不对啊.