A 57 year old male has recently been diagnosed with Hypertension. He has had high blood pressure readings in the clinic over the past 4 months; 156/92, 154/96, 162/94 and he has had similarly high readings at home. Blood tests are unremarkable and the patient has no past medical history of note. You discuss lifestyle changes with him including weight loss, healthy eating and doing regular exercise.
In terms of initiating treatment, which one of the following medications would be first line?