Which of the following is the most important reason to maintain a high level of cardiovascular health?
 a 
 A higher level of fitness allows you to live a longer, healthier life. 
 b 
 A higher level of fitness makes it easier to develop larger muscles. 
 c 
 A higher level of fitness makes you more attractive to other people. 
 d 
 A higher level of fitness improves your IQ.