Pubarche is due to
**Core Concept**
Pubarche refers to the onset of **pubic hair** growth during puberty, driven by the increase in **androgen** levels. This physiological change is a key milestone in the development of secondary sexual characteristics. The underlying mechanism involves the activation of **androgen receptors**.
**Why the Correct Answer is Right**
The correct answer is related to the role of **adrenal androgens**, such as **dehydroepiandrosterone (DHEA)**, in initiating pubarche. As the **adrenal glands** mature, they start producing more **androgens**, which stimulate **hair follicles** to grow, leading to the appearance of pubic hair. This process is independent of **gonadal** function.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not directly related to the initiation of pubic hair growth.
**Option B:** Incorrect as it is more related to the overall development of secondary sexual characteristics rather than specifically to pubarche.
**Option C:** Incorrect because, although important in puberty, it is not the primary cause of pubarche.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that pubarche is one of the first visible signs of puberty in both males and females, often preceding other secondary sexual characteristics.
**Correct Answer: D. Adrenal androgens**