Questions: A scientific theory, such as the theory of evolution, is a hypothesis likely to change. often a political position not related to science. a scientific guess or hunch. a well-founded scientific explanation.

The answer is the last one: a well-founded scientific explanation.

Explanation for each option:

1. "A hypothesis likely to change." - Incorrect. A hypothesis is an initial, testable statement or prediction, not a well-established theory. While hypotheses can change as new data is gathered, a scientific theory is a more comprehensive and well-supported explanation.
2. "Often a political position not related to science." - Incorrect. Scientific theories are based on empirical evidence and rigorous testing, not political positions.
3. "A scientific guess or hunch." - Incorrect. A guess or hunch lacks the extensive evidence and testing that underpin a scientific theory.
4. "A well-founded scientific explanation." - Correct. A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of evidence and repeatedly tested and confirmed through observation and experimentation.

Summary: A scientific theory, such as the theory of evolution, is a well-founded scientific explanation.