The correct answer is C.
An author's credentials can determine a health source's credibility. None of the other options would apply to credibility. When it comes to health, if you want to make sure that what you are researching or reading is authentic and reliable you need to find out whether the author is a professional health expert or not. You can do this by finding out their credentials.
Memory loss is not part of physical change by aging
Option D: Zen is the correct answer
Answer:
The benefits of meditating are clearing your mincd of negative thoughts; being stress free.
Explanation:
CORNEA & SCLERA ...........
