The correct answer is choice A. Monitor blood pressure and urine output closely. This is the most important nursing intervention for a client with gestational hypertension because it helps to detect any signs of worsening condition or complications such as preeclampsia, eclampsia, or HELLP syndrome. Monitoring blood pressure and urine output can also help to evaluate the effectiveness of antihypertensive medications and fluid management.

Choice B is wrong because administering antihypertensive medications as ordered is not the most important nursing intervention for a client with gestational hypertension. Antihypertensive medications are only indicated for clients with severe hypertension (systolic blood pressure ≥ 160 mm Hg or diastolic blood pressure ≥ 110 mm Hg) or those with evidence of end-organ damage. Antihypertensive medications should be used with caution and under close monitoring because they can cause adverse effects such as hypotension, fetal growth restriction, or oligohydramnios.

Choice C is wrong because encouraging bed rest and limiting activity is not the most important nursing intervention for a client with gestational hypertension. Bed rest and activity restriction have not been proven to prevent or improve gestational hypertension or its complications. In fact, bed rest can increase the risk of thromboembolism, muscle wasting, bone loss, and psychological distress in pregnant women.

Bed rest and activity restriction should only be advised for clients with severe hypertension or those with signs of fetal compromise