Let E be the set of all even integers, and let O be the set of all odd integers. Explain why Z E O. A. Every integer is both even and odd. B. Some integers are both even and odd. C. Even integers and odd integers are integers. D. Every integer is either even or odd. E. No integer is both even and odd. Solution ans : D take any integer z, z is either odd or even so, for all z , Z is a subset of EUO.