There are 6 vectors: a, b, c, d, e, f. Simply the following expression: [ a(b . c) X (e . f)d ] X [ a d ]. X represents cross product while . represents dot product. Vectors a & d are perpendicular.

There are 6 vectors: a, b, c, d, e, f. Simply the following expression

1.	There are 6 vectors: a, b, c, d, e, f. Simply the following expression: [ a(b . c) X (e . f)d ] X [ a d ]. X represents cross product while . represents dot product. Vectors a & d are perpendicular.
A.	0
B.	<strong>(b . c)(e . f) [ d + a ]</strong>
C.	<strong>(b . c)(e . f) [ d a ]</strong>
D.	<strong>(b . c)(e . f) [ d X a ]</strong>
Answer» C. <strong>(b . c)(e . f) [ d a ]</strong>