Using 143 observations, assume that you had estimated a simple regression function and that your estimate for the slope was 0.04, with a standard error of 0.01. You want to test whether or not the estimate is statistically significant. Which of the following decisions is the only correct one: a. you decide that the coefficient is small and hence most likely is zero in the population b. the slope is statistically significant since it is four standard errors away from zero c. the response of I given a change in X must be economically important since it is statistically significant d. since the slope is very small, so must be the regression R