As Shown Below,a Square Loop of Wire of Side a Moves

Multiple Choice

As shown below,a square loop of wire of side a moves through a uniform magnetic field of magnitude B perpendicular to the page at constant velocity $\overrightarrow { \mathbf { v } }$ directed to the right.Judd says that the emf induced in the loop is zero.Roger claims that it has magnitude B $\ell v$ .Which one,if either,is correct,and why?

A) Judd,because the magnetic flux through the loop is constant.
B) Roger,because the magnetic flux through the loop is constant.
C) Judd,because the magnetic flux through the loop is not constant if $\overrightarrow { \mathbf { v } } \neq 0$ .
D) Roger,because the magnetic flux through the loop is not constant if $\overrightarrow { \mathbf { v } } \neq 0$ .
E) Roger,because the magnetic flux through the loop is $\phi$ _B = 0.