This is an "If, then" statement.

What this means is...

The "if" represents a cause, and the "then" represents the effect. "If I did my calculus homework, then I will receive points for it." Doing the calculus homework is a cause. I'm causing my calculus homework to be finished. Receiving points for completing it is the effect. It's what happens when you do your homework (Don't ever skip doing homework, trust me!).

So in this case, the statement is:

"If a and b are odd integers, then a + b is an even integer."

"a and b are odd integers" is the cause. The conclusion, or the effect/outcome of the cause, is the "then" part. "a + b is an even integer."

Therefore, the answer is **B.**