Which of these sentence contains a subordinate clause? - I WILL MARK U AS THE BRAINLIEST

A)

The goal of both men was to win the election at all costs.

B)

Darkness descended on the countryside, and many stars became visible.

C)

I may seem calm before a performance, but inside I am really quite nervous.

D)

Although Spain ruled the colony for nearly 300 years, Peru won independence in 1826.