Steve claims that the sun of two off numbers is always even. How can Steve prove his conjecture?

A. Create a Venn diagram that separates the sums of odd numbers into even and odds.
B. Show one example of his claim, adding two odd numbers to form an even number
C. Create two generic odd numbers, using variables, and show that their sum is always even
D. Show fifty examples of what happens when you add two odd numbers

Please help me with this