Sunspots Are Known to Be Magnetic Phenomena Because

Multiple Choice

Sunspots are known to be magnetic phenomena because

A) Doppler shifts in spectral lines are observed.
B) the Zeeman effect is observed in sunspots.
C) collisional broadening is observed in spectral lines.
D) infrared observations indicate that the sunspots are cooler than their surroundings.
E) observations during eclipses reveal a very extensive photosphere.