Which of the following statements are true of the urination reflex? (Read carefully and select all of the correct statements.)

A)This is a flexor reflex over which we may exert voluntary control.
B)The effector of the reflex is the detrusor muscle, which contracts.
C)The stimulus for the reflex is stretching of the external urethral sphincter.
D)The part of the CNS directly involved in the reflex is the spinal cord.