**Core Concept**
In the evaluation of disorders of sex development and gonadal function, the level of testosterone is used to guide the search for underlying ovarian pathology. The sensitivity and specificity of testosterone levels can help differentiate between various causes of hyperandrogenism and hypogonadism.

**Why the Correct Answer is Right**
Testosterone levels are a useful screening tool for identifying ovarian pathology, particularly in cases of hyperandrogenism. A low testosterone level suggests ovarian failure, while a high testosterone level may indicate ovarian tumor or hyperthecosis. The ovaries produce androgens, including testosterone, and elevated testosterone levels can be a sign of ovarian pathology.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because testosterone levels are not typically used to diagnose thyroid disorders, which would be a different area of inquiry.
**Option B:** This option is incorrect because while FSH and LH levels may provide additional information about ovarian function, they are not the primary level used to guide the search for ovarian pathology.
**Option C:** This option is incorrect because testosterone levels are not typically used to diagnose adrenal disorders, which would be a different area of inquiry.

**Clinical Pearl / High-Yield Fact**
Low testosterone levels in a postmenopausal woman may indicate ovarian failure, while high testosterone levels may suggest ovarian tumor or hyperthecosis. Elevated testosterone levels can also be seen in polycystic ovary syndrome (PCOS) and other ovarian disorders.

**Correct Answer:** D.