21. Siobhan has been in a committed relationship for 12 years and married for the past five. She and her spouse have what both regard as a satisfying sex life, but Siobhan is concerned when she learns that other couples their age have sex more often. If Siobhan were to ask her healthcare provider for advice, they would likely recommend:
a. no treatment at all
b. psychoanalysis
c. sensate focus therapy
d. hormone treatment