On dividing 190 by a number, the quotient is 9 and the remainder is 1. Find the divisor? Select.
A) 12 B) 15 C) 16 D) 17 E) 21

Rationale: "d = ( d - r ) / q = ( 190 - 1 ) / 9 = 189 / 9 = 21 e )"
Answer: E