Which sentence contains parallel structure?
A. As the day slowly dwindled down and people returned home, the town took on an empty feeling.
B. The chirping of birds brought a smile to everyone's faces because the sound meant spring had arrived.
C.
The courage of others can serve as a great inspiration when you are not sure you have it yourself.
D.
In times of difficulty, in times of need, in times of sadness, your true friends will be there.