John will be x in 7 years. How old was he last year?

A: x + 7

B: 1 - x - 7

C: x + 8

D: x - 8

D is the answer, because seven minus X is his age this year and a year before that is last year. So the answer is X-8

Right now, he is 7 less than he will be in 7 years, and 1 more than he was last year.

'x' is 7 more than he is right now, and 8 more than he was last year.

If 'x' is 8 more than he was last year, then he was (x - 8) last year.

That's Choice-'D'.