A physical education professor believes that exercise can slow the aging process. For the past 10 years, he has been conducting an exercise class for 14 individuals who are currently 50 years old. Normally as one ages, maximum oxygen consumption decreases. The national norm for maximum oxygen consumption in 50-year old individuals is 30 milliliters per kilogram per minute, with a SD of 8.6. The mean of 14 individuals sampled is 40 milliliters per kilogram per minute. Using alpha = .05, one tailed what do you conclude?

a) exercise does not influence maximum oxygen consumption in older adults

b) exercise causes an increase in maximum oxygen consumption in older adults

c) exercise causes a decrease in maximum oxygen consumption in older adults

d. none of the above