The Maunder minimum is the name given to the

A) unexpectedly low number of neutrinos observed from the sun
B) region of lowest temperature in the photosphere, between the decreasing temperature in the solar interior and the increasing temperature in the chromosphere
C) Period of 70 years in the 1600s and early 1700s during which essentially no sunspots were seen.
D) Minimum in the number of sunsoits that occurs roughly every 11 years.