Which decision are people most likely to face in their twenties?

a. which health-care specialist do i want to see?

b. how should i reinvest my finances?

c. which career do i want to pursue?

d. which sport do i want to play?

It would most likely be C due to the age range. 

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.