I don't know how to -------------the problem 单项选择 A work at B deal with C work for D deal t

I don't know how to -------------the problem 单项选择 A work at B deal with C work for D deal t
I don't know how to -------------the problem 单项选择 A work at B deal with C work for D deal t

I don't know how to -------------the problem 单项选择 A work at B deal with C work for D deal t
B deal with
（A是从事于……
B是处理
C是为...效力）
how to后接动词原形可以排除最后一项.