A project manager wanted to build a linear regression model between time required to end a certain activity the required expenses in CAN$. The R squared was found to be 0.206169 and the variance of the expenses = 1.480072 and the variance of the required time = 1.796659. Moreover, he calculated the standard error of the slope and it was 0.101883. He checked the significance of the slope and found it one of the following findings: a. positive but insignificant at 95% confidence level b. negative but insignificant at 95% confidence level c. negative and significant at 95% confidence level d. positive and significant at 95% confidence level