**Core Concept**
During sexual differentiation in males, the presence of the Y chromosome triggers the production of androgens, specifically testosterone, which promotes the development of male reproductive organs. This process involves a complex interplay of genetic, hormonal, and enzymatic factors.

**Why the Correct Answer is Right**
The SRY gene on the Y chromosome encodes a protein that triggers the expression of SOX9, a transcription factor essential for testis development. SOX9, in turn, upregulates the expression of anti-Müllerian hormone (AMH), which inhibits the development of Müllerian ducts in males. The production of testosterone by Leydig cells in the testes promotes the growth of male external genitalia. The enzyme 5-alpha-reductase converts testosterone into dihydrotestosterone (DHT), a more potent androgen that is crucial for the development of male external genitalia.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the process of sexual differentiation in males.
**Option B:** This option is incorrect because the development of male reproductive organs is not solely dependent on the presence of testosterone.
**Option C:** This option is incorrect because the development of female reproductive organs is not relevant to the process of sexual differentiation in males.

**Clinical Pearl / High-Yield Fact**
The presence of the SRY gene on the Y chromosome is a critical determinant of male sex determination, and mutations in this gene can lead to sex reversal or other developmental abnormalities.

**Correct Answer:** D.