Only b. x+1, x+3 as long as x is an odd integer
a. x+1, x+2, wouldn't be consecutive even integers. If x is odd (e.g. 1), then 1+1=2 would be even but, 1+2=3 would be odd.
c. 2x, 2x+1, wouldn't be the answer. 2x will certainly be even but 2x+1 is going to be odd.
