If a = -2i - 4j + 4k and B $\sqrt { 2 ( \mathbf { j } - \mathbf { k } ) }$

Multiple Choice

If A = -2i - 4j + 4k and B = i - 2j + 2k, the vector of magnitude 2 that is perpendicular to both A and B is

A) (j + k) .
B) $\sqrt { 2 ( \mathbf { j } - \mathbf { k } ) }$
C) $\sqrt { 2 ( \mathbf { j } + \mathbf { k } ) }$
D) (j - k) .