The correct answer is A. The debate team has many new members, and the team is not very good yet.
Explanation:
In grammar, faulty coordination occurs as two or more complete ideas are not connected logically usually because the ideas do not have the same importance but are connected as if they did or because the element that connects them is not appropriate. This occurs in the case of "The debate team has many new members, and the team is not very good yet" because the idea "The debate team has many new members" and the idea "the team is not very good yet" are not equivalent, indeed they represent a contrast and would be logically connected by using a conjunction such as "but" not by using "and".
