Final answer:
Essential hypertension may result from a high salt diet, which can lead to increased blood volume and blood pressure.
Step-by-step explanation:
Essential hypertension may result from a high salt diet. When blood pressure increases, renin is released from the liver, which activates the renin-angiotensin-aldosterone system (RAAS).
This system ultimately leads to increased reabsorption of sodium and water, leading to increased blood volume and blood pressure.
Therefore, option A, high salt diet, is a possible cause of essential hypertension.