Conde Nast is a publisher of many magazine brands. An analyst fit a regression model to predict the cost of a full page, black and white ad (y) from the magazine's calculation (x), based on Conde Nast rates for 15 of its magazines in 2008. The resulting estimated regression line is :

y=24.90+0.024x

Where both circulation and ad cost are given in thousands. Suppose that the standard error of the slope is 0.003. Is there evidence that cost of an ad is related to circulation?

a) Yes because b1 is not zero

b) No because b1 is not zero

c) Yes because b1/SEb1 is about 8