The statement that best explains why the Civil War continued after the Confederate surrender at Appomattox Court House is: The Battle of Palmito Ranch happened in Texas a month later.
While the Confederate surrender at Appomattox in April 1865 marked a significant turning point in the war, communication and movement were slower in the western territories, leading to continued fighting in places like Texas. The Battle of Palmito Ranch, which took place in May 1865, is notable for being one of the last battles of the Civil War, despite the larger surrender of Confederate forces.