On dividing 171 by a number, the quotient is 8 and the remainder is 3. Find the divisor.  Select:	A) 18	B) 19	C) 20	D) 21	E) 22

Rationale: "d = ( d - r ) / q = ( 171 - 3 ) / 8 = 168 / 8 = 21 d"
Answer: D