Q. A 20-year-old boy was brought to the ER by an ambulance after he collapsed on the football field. The paramedics report that the patient lost consciousness for 2 minutes. His loss of consciousness was not associated with confusion, lethargy or sleepiness after the incident. He reports that he has had episodes of lightheadedness and mild generalized chest pain before while playing soccer, but never severe enough to seek medical attention. The patient’s past medical history is insignificant. He is not taking any medications or drugs and does not use tobacco or consume alcohol. The patient’s family history is significant for heart disease as his grandfather died from a heart attack at 45 years. His blood pressure is 130/80 mmHg and pulse 70/min. A physical examination reveals a 4th heard sound at the cardiac apex and a mid-systolic murmur over the left lower sternum. No radiation towards the neck or base of heart was noticed. Which of the following medications would help this patient?