After receiving instruction on the use of a diaphragm for contraception, which statement by the client indicates that they have understood the teaching?

A. Leaving the diaphragm in for 6 hours post-intercourse allows sperm to be effectively blocked, reducing pregnancy risk. B. "I can leave the diaphragm in for a day or two." → The diaphragm should not be left in for more than 24 hours due to infection risk. C. "Once I am fitted for the diaphragm, it will always be the correct size." → Diaphragm size must be refitted after weight changes, childbirth, or pelvic surgery. D. "This contraceptive can be used during menstruation." → Not recommended due to infection risk.