下列句子中，哪一句是你认为是不正确的。说不正确，指不符合（你们那里的）口语说法？

A. There is a person in our group who does that all the time.

B. There is a person in our group that does that all the time.

C. There is this person in our group, he/she does that all the time.

D. There is this person in our group, who does that all the time