Exercise increases muscle mass. Regular exercise reduces resting heart rate. People should exercise because it makes them feel better. Those who exercise regularly can increase their life span.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: The following statements are from an article in a fitness magazine. Which of these is an opinion?
Possibilities:
- Exercise increases muscle mass.
- Regular exercise reduces resting heart rate.
- People should exercise because it makes them feel better.
- Those who exercise regularly can increase their life span.

People should exercise because it makes them feel better.