Read the excerpt from "George Washington.”

He realized early that the best strategy was to harass the British. He reported to Congress, "we should on all occasions avoid a general action, or put anything to the risque, unless compelled by a necessity, into which we ought never to be drawn." Ensuing battles saw him fall back slowly, then strike unexpectedly. Finally in 1781 with the aid of French allies—he forced the surrender of Cornwallis at Yorktown.

Which provides the best objective summary of this excerpt?

a. Washington’s key battle strategy of harassment against the British led to the surrender of Cornwallis in 1781.
b. If it were not for America’s French allies, Washington would not have been able to force the surrender of Cornwallis.
c. Washington made many speeches to Congress during the war against the British while he was an army commander.
d. Finally in 1781—with the aid of French allies—Washington forced the surrender of Cornwallis at Yorktown.