The correct answer is B) Not pursuing his retreats
A continued error of General Lee's enemies was not pursuing his retreats.
General Robert E. was the leader of the Confederate army during the United States Civil War. During the war, he encountered hardships and difficult situations but his experience in previous wars such as the invasion Veracruz, Mexico, his intelligence, courage, and wit, made him resolve many of those situations. In some of those situations where the Confederate Army had to retire, the Union Army could have stricken a definitive defeat, but a continued error of General Lee's enemies was not pursuing his retreats.
The other options of the question were A) Overestimating his talents, C) Being unaware of his other generals, and D) Not recognizing his loyalty to the Confederacy.