—Whose basketball is it? —It might be . They both like playing basketball.A. Bob and Bill

—Whose basketball is it?
—It might be . They both like playing basketball.
A. Bob and Bill B. Bob and Bill’s C, Bob’s and Bill D. Bob’s and Bill’s

解析：句意：这是谁的篮球？它可能是鲍勃和比尔的。他们都喜欢打篮球。表示两者共同拥有的人或物（共有）时，只需要后一个名词加's（或'）即可。如果表示两者各自的所属关系（各自所有），则每个名词词尾都加上's（或'）根据句意，本句表达两人共有。故选B。

谢谢了