The Average Age of Trees in a Large Local Park

The average age of trees in a large local park is 60 years, with a standard deviation of 2.2 years. A simple random sample of 400 trees is selected, and the sample mean age x̄ of these trees is computed. Which of the following statements about this scenario is true?

A) The average age of 60 years is a parameter.
B) The standard deviation of 2.2 years is a parameter.
C) Neither the average age of 60 years nor the standard deviation of 2.2 years is a parameter.
D) Both the average age of 60 years and the standard deviation of 2.2 years are parameters.