The correct answer is D) He called for additional troops and put General George B. McClellan in command.
President Lincoln responded to the Union retreat at the Battle of Bull Run in that he called for additional troops and put General George B. McClellan in command.
On July 21, 1861, the Union Army and the Confederated Army fought the Battle of Bull Run, in Manassas, Virginia. Although the Army Union outnumbered the Confederates, the strategy of the Southern Army was far better and at the end of the day, the Union Army had to retreat. It boosted the confidence of the Confederates and open many interrogations in the North. President Abraham Lincoln removed General McDowell from command after the disastrous loss, and put General George B. McClellan in place with the order to reorganize the troops and call more and better soldiers.