A random sample of 169 bottles of cologne showed an average content of 5 ounces. It is known that the standard deviation of the contents (i.e., of the population) is 0.39 ounces.
The point estimate of the mean content of all bottles is ____

a. 0.39 ounces
b. 169 ounces
c. 0.03 ounces
d. 5 ounces