AP bio experts, help!?!?

The answer is B. A male cat would have only one copy each of the X and Y chromosomes, while a female cat has two copies of the X chromosome. Keeping in mind that a male cat inherits the Y chromosome from his father and the X chromosome from his mother, the tortoise shell condition could have only resulted from his mom being a tortoise shell cat as well, since the Y chromosome has nothing to do whatsoever with the condition.