Final answer:
To best support the thesis that walking has benefits for both the cardiovascular system and the mind, the writer should include evidence linking walking to a reduced risk of heart disease and the release of endorphins during walking.
Explanation:
The writer should add the following piece of evidence to best support the thesis:
- OB. Walking can reduce the risk of heart disease, according to a recent study.
- D. Endorphins released during walking build brain cells and make people feel good.
- The evidence from the recent study linking walking to a reduced risk of heart disease reinforces the cardiovascular benefits of walking, supporting the thesis.
Learn more about supporting a thesis with evidence here:
https://brainly.com/question/41904369