What is the most significant benefit of exercising regularly?
a. physical fitness
b. less fatigue
c. improved mood
d. increased flexibility

The correct answer is A - the most significant benefit of regular exercise is the resultant physical fitness that will come with this.

Physical fitness and a healthy lifestyle are the most important things that a person wants.

The more he or she exercises, the better their fitness levels. There are obviously other benefits too but this is the most important one and these will all come as a result of that increased physical fitness.

d would be your answer