They became nerve cells. They became red blood cells. They became bone cells. They became skin cells.
I gave my students this multiple choice question: Stem cells are cells that can differentiate into many different kinds of cells. Scientists have discovered that the environment supporting the cells influences stem-cell differentiation. For example, stem cells grown on strong, flexible surfaces became muscle cells. What most likely happened to stem cells grown on a hard, rigid surface?

Only one answer is correct among these 4 choices:
- They became nerve cells.
- They became red blood cells.
- They became bone cells.
- They became skin cells.

Could you tell me which one is correct?

They became bone cells.