The Sunspot Cycle on the Sun Is A(n)

The sunspot cycle on the Sun is a(n)

A) regular movement of a relatively constant number of sunspots from the poles to the equator of the Sun over an 11-year period.
B) somewhat irregular cycle of buildup and decay of sunspot numbers, averaging about 11 years and with a variable number of sunspots for each cycle.
C) extremely regular buildup and decay in the number of sunspots, with a precise period of 11 years but with widely varying numbers of sunspots
D) Extremely regular buildup and decay in the number of sunspots, with a precise period of 11 years with every cycle having the same number of sunspots at maximum.