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.
It means shadow in English
Confused and engaged. touch, sight, and mind
I think the answer is
A. participating in an activity you enjoy
Carbs is a short and version of carbohydrates
