Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The results showed that the average tread life was 53,709 miles with a standard deviation of 3,471 miles. What is the best estimate of the average tread life in miles for the entire population of these tires?
A.(53,709/100)
B.3,471
C.(3,471/100)
D.53,709