According to the question;

In one’s place B + 3 = 0

⇒ B is the number whose addition with 3 gives 0 in a one’s place.

⇒ B = 7 (7 + 3 = 10 and one’s place of 10 is 0 )

In ten’s place A + 8 + 1 = 15 ( 1 is the carry from B + 3)

⇒ A + 9 = 15

⇒ A = 15 – 9 = 6

∴ A + B = 6 + 7 = 13.

Hence the option (a) is correct.