Please help
Identify the compound sentence from the choices below:
A. "If a man doesn't keep pace with his companions, perhaps it is because he hears a different drummer." (Henry David Thoreau)
B. "A man may die, nations may rise and fall, but an idea lives on." (John F. Kennedy)
C. "I was relaxed on the tree trunk, ensconced in the lap of lichen, watching the lily pads at my feet tremble and part dreamily over the thrusting path of a carp." (Annie Dillard)
D. "After climbing a great hill, one only finds that there are many more hills to climb. " (Nelson Mandela)