Given below are four jumbled sentences. Select the option that gives their correct order.

A. On the arch hung an old board with the newly painted letters "Post Office."

B. The old man went in quietly and squatted on the veranda.

C. The voices of two or three people busy and their routine work could be faintly heard through the wall.

D. When Ali sighted the earth-brown partridge, almost invisible to other eyes, the poor bird, they said, was as good as in his bag.