\textbf{A copy machine dealer has data on the number x of copy machines at each of 89 customer locations and the number y of service calls in a month at each location. Summary calculations give $$\bar{}x$$ = 8.4, $$S\_x$$ = 2.1, ȳ = 14.2, $$S\_y$$ = 3.8, and r = 0.86. What is the slope of the least squares regression line of number of service calls on number of copiers?} 
选项为:A:$$0.86$$  B:$$1.56$$  C:$$0.48$$  D:None of the above  E:\textbf{Can't tell from the information given}  请回答其中一个选项.