A resting heart rate is 60-100bpm for the average adult. Generally, a lower resting heart rate implies more efficient heart function and better fitness. I'm not sure on the second part, sorry.
C should be the right awnser if not than its B
Answer: Weak tooth enamel.
Explanation: Bulimia nervosa is a serious eating disorder that consists of eating large amounts of food and then purges to get rid of extra calories. As you might know, when you throw up, some acid in your stomach also goes out with the food. This stomach acid weakens your tooth enamel.