Which of the following statements about the supported way of MySQL DB for backup are true? (the number of correct answers: 2)

Which of the following statements about the supported way of MySQL DB for backup are true? (the number of correct answers: 2)
A . you can use ‘mysqldump’ do logical backup
B . you can copy files directly to do physical backup
C . you can use ‘binlog’ to do real time backup
D . you must stop accessing to DB before you do logical backup

Answer: A,B