with a lot of difficult problems ( ),the man felt like a cat on a hot brick.A settling B settledwith a lot of difficult problems ( ),the man felt like a cat on a hot brick.A settling B settled C to settle D being settled.这里答案是C,为什么其他答案不对呢,求理由,另外我想问下如果有are settled,是不是也可以选择.

with a lot of difficult problems ( ),the man felt like a cat on a hot brick.A settling B settled
with a lot of difficult problems ( ),the man felt like a cat on a hot brick.A settling B settled C to settle D being settled.这里答案是C,为什么其他答案不对呢,求理由,另外我想问下如果有are settled,是不是也可以选择.