The manager,（ ）his study of the situation, was ready to talk abo

The manager,（ ）his study of the situation, was ready to talk about it when I arrived.
A、has completed
B、have completed
C、having completed
D、had completed
【正确答案】：C
【题目解析】：句子后面已经有谓语动词了，所以此处只能填非谓语，从而可排除选项A，B和D。