In a comprehensive road test on all new car models, one variable measured is the time it takes a car to accelerate from 0 to 60 miles per hour. To model acceleration time, a regression analysis is conducted on a random sample of 129 new cars. Given: R^2= 0.6960 Approximately what percentage of the sample variation in acceleration time can be explained by the simple linear model? a. 8%
b. -17%
c. 0%
d. 70%