8. A square loop of wire, of side a, lies midway between two long wires, 3a apart, and in the same plane. (Actually, the long wires are sides of a large rectangular loop, but the short ends are so far away that they can be neglected.) A clockwise current I in the square loop is gradually increasing: dI/dt = k (a constant). Find the emf induced in the big loop. Which way will the induced current flow?

(A)μ₀ka ln2/π, counterclockwise

(B)μ₀ka ln2/π, clockwise

(C)μ₀ka ln2/(2π), counterclockwise

(D)μ₀ka ln2/(2π), clockwise