Which Statement Is NOT True of the Urinary Bladder

Multiple Choice

Which statement is NOT true of the urinary bladder?

A) The detrusor muscle is smooth muscle that contracts to empty the bladder.
B) The trigone is on the floor of the bladder and does not expand.
C) The rugae of the mucosa permit expansion of the lining.
D) The internal urethral sphincter is smooth muscle that contracts to permit urination.