The answer to the question is D. The sum of two irrational numbers cannot be rational. For example, pi plus pi is not going to be a rational number. The product of a rational and irrational number is not always rational. For example, if you multiply 6/5 and pi, you will not get a rational number. The sum of two rational numbers also cannot be irrational, because the original numbers are rational. This leaves only D available. Hope this helps!
