a) DepressionThe nurse should instruct the client that depression is a common adverse effect of combined oral contraceptives. Other common adverse effects of the medication include amenorrhea, weight gain, headache, nausea, breakthrough bleeding, and breast tenderness.Fluid retention can occur due to an excess of estrogen. Polyuria is not a common adverse effect of the medication.Hypertension, rather than hypotension, is a common adverse effect of combined oral contraceptives.Urticaria is not a common adverse effect of combined oral contraceptives.