The child ____on the chair and eating a cake .A sitting B is sitting

题目

The child ____on the chair and eating a cake .A sitting B is sitting
why?

答案

B
句中缺少谓语,而sitting是现在分词或动名词,不能在句中独立作谓语.is sitting是现在进行时,在句中作谓语.
句意：那个小孩正坐在椅子上吃着一个蛋糕.