Usually when working with probabilities of this type we do not subtract, so our answer is not A.
As the numerator is divided, or out of something, we do not add it. Therefore C will not be our answer either.
The total number of outcomes is the denominator, so D is incorrect. The favorable outcome is the probability we are thinking of, so four even numbers. 4 is the favorable outcome and the numerator, so the answer is B.
