The magnetic field perpendicular to the plane of a conducting ring of radius `r` change ate the rate `(dB)/(dt)`
A. The emf induced in the ring is `pir^(2)(dB)/(dt)`
B. The emf induced in the rintg is `2pir(dB)/(dt)`
C. The potential difference between diametrically opposite points on the ring is half of the induced emf.
D. All points on the ring are at the same potential.