QUICK: A circular loop of radius r is rotated through a magnetic field B, which of the following would increase the magnetic flux through the loop by a factor of 16?
 SELECT ALL THAT APPLY
 A. Doubling B and quadrupling r.
 B. Quadrupling B and doubling r.
 C. B remains constant and quadrupling r.
 D. Doubling B and doubling r.