Interpret solutions of trigonometric equations in context

The function

R (t)

models the average number of days of precipitation in Mogadicio, Somalia on the

t^{th}

month of the year.

R (t) = - 12 \cos (\frac{π}{6} (t - 2)) + 13.2

What does the solution set for $y = - 12 \cos (\frac{π}{6} (7 - 2)) + 13.2$ ‍ represent?

(Choice A)
The month with the minimum number of days of precipitation
(Choice B)
The number of months with an average of $7$ ‍ days of precipitation
(Choice C)
The set of months with an average of $7$ ‍ days of precipitation
(Choice D)
The average number of days of precipitation in the $7^{th}$ ‍ month of the year

Precalculus