Evaluate each of the following statements:

a. "In a multiple regression model, the coefficients on the explanatory variables measure the percent of the total variation in the dependent variable Y explained by that explanatory variable."

b. "The more degrees of freedom in the regression, the more likely it is that a given t-ratio exceeds the critical t-value."

c. "The coefficient of determination (R2) can be exactly equal to one only when the sample regression line passes through each and every data point."