【单选题】Which of the following sentences is a compound sentence?
A.
The rich soil of river-made favoured the growth of a thickly settled farming population and this farming population had been united into a highly civilized kingdom.
B.
Of course, they could not see with their eyes, but they thought that by touching him they could learn just what kind of animal he was.
C.
The idea of Harry's getting a job as a travelling salesman doesn't appeal to his wife.
D.
The bird which the fox was looking at hungrily was a cock.