Any number that you can completely write down on paper using digits ... and a fraction bar or decimal point if necessary ... is a rational number. If you add it to 0.5, then the sum is another rational number.
I would say A (7) but I’m not 100% sure.
(4 hundred + 0 tens + 5 ones) + (1 ten) = 4 hundred + 1 ten + 5 ones
... = 415
