D
if you find the area of all of the squares with numbers telling you the length or width they equal 626, but there is only one box without one of the numbers because it has a length of 18. So with that you can write that 626 + 18x(x being the missing number) = (one of the options), and after trying all the options D is the only one with a reasonable number (which is 7) and 7×18= 126 and if we go back up and add that to 626 it equals 752
