Final answer:
Primary hypertension is associated with Differences in genes that affect sodium retention. (option b)
Step-by-step explanation:
Primary hypertension, also known as essential hypertension, often involves a complex interplay of genetic and environmental factors. Option b, "Differences in genes that affect sodium retention," aligns with the understanding that variations in genes influencing sodium handling by the kidneys can contribute to increased blood pressure. Sodium plays a crucial role in fluid balance, and genetic factors affecting its retention or excretion can impact blood pressure regulation. This is a key aspect of primary hypertension, where no specific underlying medical condition is identified as the cause.
Options a, c, and d are not typically associated with primary hypertension. Vasopressin and nitrous oxide, when dysregulated, may influence blood pressure, but they are not primary factors in essential hypertension. Similarly, decreased production of angiotensinogen is not a characteristic feature of primary hypertension. Option e mentions Type 1 diabetes, which, while affecting blood pressure, is usually considered secondary hypertension.
Differences in genes influencing sodium retention are a significant factor associated with primary hypertension, highlighting the genetic component in the development of elevated blood pressure.