When he came to,he found himself ___ on a chair,with his hands ___ back.

When he came to,he found himself ___ on a chair,with his hands ___ back.
A.to sit; tying B.sitting; tied C.sit being tied D.sat was tied
选B
我知道为什么选sitting,但是后面不能用being tied 被绑着,这样不行么?