A Solar Plage Is A

A solar plage is a:

A) cooler region of the photosphere surrounding the very cold central region of a sunspot.
B) brightening of a portion of the Sun in light from hydrogen and other atomic species, appearing just before a sunspot and then surrounding it.
C) "hole" in the hot corona through which solar wind escapes into interplanetary space.
D) gigantic loop of gas, lifted by magnetic fields above the solar surface, appearing dark against the photosphere and bright against dark space.