If O is the origin and A and B are, respectively, (a1, b1) and (a2, b2), then OA⋅OB sin(AOB) is equal to
(A) a1a2 + b1b2
(B) a1b2 + a2b1
(C) a1b2 − a2b1
(D) a1a2 − b1b2
Correct option(C) a1b2 − a2b1
See Fig.