There Is an Old Saying in Golf: "You Drive for Show

There is an old saying in golf: "You drive for show and you putt for dough." The point is that good putting is more important than long driving for shooting low scores and hence winning money.To see if this is the case,data on the top 69 money winners on the PGA tour in 1993 are examined.The average number of putts per hole for each player is used to predict the total winnings (in thousands of dollars) using the simple linear regression model (1993 winnings) _i = $\beta$ ₀ + $\beta$ ₁(average number of putts per hole) _i + $\varepsilon$ _i,
Where the deviations $\varepsilon$ _i are assumed to be independent and Normally distributed with a mean of 0 and a standard deviation of $\sigma$ .This model was fit to the data using the method of least squares.The following results were obtained from statistical software. The quantity s = 281.8 is an estimate of the standard deviation $\sigma$ of the deviations in the simple linear regression model.What are the degrees of freedom for this estimate?

A) 66
B) 67
C) 68
D) 69