A Long Straight Wire Is Parallel to One Edge and Is

A long straight wire is parallel to one edge and is in the plane of a single-turn rectangular loop as shown.If the loop is changing width so that the distance x changes at a constant rate of 4.0 cm/s, what is the magnitude of the emf induced in the loop at an instant when x = 6.0 cm? Let a = 2.0 cm, b = 1.2 m, and I = 30 A.

A) 5.3 $\mu$ V
B) 2.4 $\mu$ V
C) 4.8 $\mu$ V
D) 2.6 $\mu$ V
E) 1.3 $\mu$ V