2003 * 2004 – 2001 * 2002 = _________?

A. 8000
B. 8010
C. 8020
D. 8040
Explanation:
(2000 + 3)(2000 + 4) – (2000 + 1)(2000 + 2) = ?
Since (2000 * 2000) – (2000 * 2000) is equal to zero. ?
= (8000 + 6000 + 12) – (4000 + 2000 + 2)
=> ? = 14012 – 6002 = 8010