**Core Concept**
The development of sarcoma in a fibroid uterus is a rare but significant complication. Fibroids are benign tumors of the smooth muscle and connective tissue in the uterus, but in some cases, they can undergo malignant transformation.

**Why the Correct Answer is Right**
The risk of sarcoma developing in a fibroid uterus is estimated to be around 1 in 800 to 1 in 1,000. This is because fibroids can undergo genetic mutations that lead to the development of leiomyosarcoma, a type of uterine sarcoma. The exact mechanism is not fully understood, but it is thought to involve alterations in the TP53 and CDKN2A genes, which are tumor suppressor genes. These genetic changes can lead to uncontrolled cell growth and tumor formation.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely incorrect because it does not provide a specific risk estimate, making it difficult to evaluate its accuracy.
**Option B:** This option is likely incorrect because it is too high, exceeding the established risk estimate of 1 in 800 to 1 in 1,000.
**Option C:** This option is likely incorrect because it is too low, being significantly lower than the established risk estimate.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the risk of sarcoma developing in a fibroid uterus is higher in women with multiple fibroids, a family history of uterine cancer, or a personal history of radiation exposure.

**Correct Answer: D. 1 in 800 to 1 in 1,000**