## **Core Concept**
The development of the external genitalia in the embryo involves the formation of the clitoris in females and the penis in males, both of which arise from the same primordial structures. The genital tubercle is a critical structure in early embryonic development that gives rise to external genitalia.

## **Why the Correct Answer is Right**
The clitoris develops from the **genital tubercle**, which is an embryonic structure that forms early in fetal development. During female sexual differentiation, in the absence of testicular hormones (such as testosterone and anti-Müllerian hormone), the genital tubercle proliferates and eventually forms the clitoris. This process is influenced by the presence of estrogen.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Incorrect because, although the urogenital folds are involved in the development of the female external genitalia, they primarily contribute to the formation of the labia minora, not the clitoris.
- **Option B:** Incorrect as the genital swellings contribute to the formation of the labia majora, not the clitoris.
- **Option C:** This seems to be a placeholder and does not directly relate to a specific developmental structure; however, based on standard embryological knowledge, it does not pertain to clitoris development.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that both male and female external genitalia develop from the same basic structures: the genital tubercle, urogenital folds, and genital swellings. The differentiation into male or female external genitalia is primarily determined by the presence or absence of specific hormones.

## **Correct Answer:** D. Genital tubercle.