Answer
(a) equal to
(b) II
Work Step by Step
(a) First we find the magnitude of the two vectors
$|1.4\vec A|=|1.4(-2.2m)\hat x|=3.1m$
Now the magnitude of the second vector is given as
$|2.2\vec B|=|2.2(1.4m)\hat y|=3.1m$
Thus the magnitudes of both given vectors are equal.
(b) The best explanation is II. A number and its negative have the same magnitude.
