What are stem cells primarily known for?

Stem cells are primarily known for their ability to differentiate into various cell types, making them crucial for growth, development, and the repair of tissues. Specifically, they can develop into specialized cells that serve different functions in the body, such as muscle cells, nerve cells, and blood cells.

Bone marrow is a significant source of stem cells, particularly hematopoietic stem cells, which can develop into various types of blood cells, including red blood cells, white blood cells, and platelets. This multifunctional capacity is critical for maintaining and regenerating tissues after injury or illness.

The other options focus on limitations or specific functions of cells. The notion that stem cells cannot differentiate contradicts their defining characteristic. Similarly, stating that they only produce red blood cells and that they exclusively repair muscle tissue does not encompass their broader capabilities. Stem cells possess the potential to become many types of cells, not restricted to a single lineage or function, which is why option B accurately reflects their primary role.