Question

which of the following methods of contraception must be coordinated carefully with the womans menstrual cycle in order to be effective?
iud
diaphragm
abstinence
rhythm

Explanation:

The rhythm method, also known as natural family - planning, relies on tracking the woman's menstrual cycle to identify fertile and infertile periods. IUDs are inserted and remain effective regardless of the cycle, diaphragms are used during intercourse and not cycle - dependent, and abstinence is not related to cycle coordination for effectiveness.

Answer:

D. Rhythm