The correct answer is A) General Johnston was wounded while fighting at the Battle of Seven Pines.
General Lee was asked to replace General Johnston because General Johnston was wounded while fighting at the Battle of Seven Pines.
General John E. Johnston (1807-1891) was a military officer on the side of the Confederates during the American Civil War. After commanding an important victory at the First Battle of Bull Run in 1861, he was severely wounded in June 1862, at the Battle of the Seven Pines. He was replaced by General Robert E. Lee.
