When General George Pickett was asked to regroup his division after "Pickett's Charge," he was not able to because

A more than half of the Confederate soldiers involved in the charge were dead, wounded, or captured.
B he had already called for his soldiers to be released from the army.
C the soldiers had been sent to places such as Little Round Top, the Wheatfield, and Devil's Den.
D his cavalry became lost and were nowhere to be found.