巴甫洛夫把人的神经活动分成许多类型，其中有四种典型类型与气质类型对应：强、不均衡型为胆汁质；强、均衡、灵活型为多血质；强、均衡、不灵活型为粘液质；弱型为抑郁质。(心理学)

Helen was fully occupied_____business matters, so we didn’t want to brother her.

A．for

B．at

C．in

D．with