**Core Concept**
Bone metastasis is a common complication of various cancers, often requiring palliative treatment to alleviate pain and improve quality of life. The management of bone metastasis involves the use of radioisotopes that selectively target cancer cells in the bone, reducing pain and bone destruction.

**Why the Correct Answer is Right**
Technetium-99m (Tc-99m) and Strontium-89 (Sr-89) are the preferred radioisotopes for the management of bone metastasis. **Tc-99m** is a metastable nuclear isomer used in bone scintigraphy to identify areas of increased bone turnover, which can be indicative of metastatic disease. **Sr-89**, on the other hand, is a beta-emitting radioisotope that selectively accumulates in areas of high bone turnover, emitting beta particles that destroy cancer cells in the bone. This leads to a reduction in bone pain and improvement in quality of life.

**Why Each Wrong Option is Incorrect**
* **Option A:** Technetium-99m is primarily used for diagnostic imaging, not therapeutic purposes.
* **Option B:** Radium-223 is used for the treatment of castration-resistant prostate cancer with bone metastases, but it is not the preferred radioisotope for all types of bone metastasis.
* **Option D:** Iodine-131 is a radioisotope used in the treatment of thyroid cancer, not bone metastasis.

**Clinical Pearl / High-Yield Fact**
When managing bone metastasis, it is essential to use radioisotopes that selectively target cancer cells in the bone, reducing damage to surrounding healthy tissues.

**Correct Answer: C. Strontium-89 (Sr-89) is the preferred radioisotope for the management of bone metastasis.**