Mrs. Stevenson was taking amlodipine 10 mg daily for her hypertension and while it controlled her blood pressure well, she could not tolerate the lower extremity edema. She was converted to losartan 100 mg daily., which is the dose ceiling for losartan. While she did not have any adverse effects with losartan, her blood pressure never achieved goal. Which of the following statements best characterizes clinical comparison of the two medications?
a. Amlodipine is more efficacious than losartan
b. Amlodipine is more potent than losartan
c. Neither medication has acceptable efficacy
d. Neither medication has acceptable potency.