The answer to your question is: A) Your food journal.
It's best to use a food journal to keep track of the things you've eaten, and how much calories you've eaten throughout that day. Using a journal can help you when your on a diet so you can keep track of what you've been eating.
I hope this helps you!
Have a wonderful day!
-LizzyIsTheQueen
The other two components of the health triangle are C, Physical health, and D, Social health.
Breathing, and lungs. They are the most important.