**Core Concept**
Anti-Müllerian hormone (AMH) or Müllerian inhibiting substance (MIS) is a protein hormone that plays a crucial role in the development and regression of the Müllerian ducts in the embryo. It is essential for the development of the male reproductive system and is secreted by a specific type of somatic cell in the testes.

**Why the Correct Answer is Right**
The correct answer is **Sertoli cells**. AMH/MIS is secreted by Sertoli cells in the testes, which are somatic cells responsible for the nourishment and support of developing sperm cells. Sertoli cells produce AMH/MIS in response to follicle-stimulating hormone (FSH) from the pituitary gland, and this hormone then inhibits the growth and development of the Müllerian ducts in the embryo. This process is essential for the formation of the male reproductive system, including the epididymis, vas deferens, and seminal vesicles.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the correct answer is not listed. Sertoli cells are the primary source of AMH/MIS in the testes.
* **Option B:** This option is incorrect because Leydig cells, also known as interstitial cells, are responsible for producing testosterone in the testes, not AMH/MIS.
* **Option C:** This option is incorrect because the adrenal glands produce a variety of hormones, including androgens, but not AMH/MIS.
* **Option D:** This option is incorrect because the ovaries produce estrogen and progesterone, but not AMH/MIS.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that AMH/MIS is a marker of follicle depletion in women, and its levels are often used to assess ovarian reserve in fertility evaluations.

**Correct Answer:** D. Sertoli cells.