Answer:
Option D
Explanation:
Given : Graph of the function-

To find : Which describe the best expression
A. The graph has an initial value of 20, and each successive term is determined by subtracting 1/3 .
This denote that

B. The graph has an initial value of 20, and each successive term is determined by multiplying by 1/3 .
This denote that

C. The graph has an initial value of 60, and each successive term is determined by subtracting 1/3 .
This denote that

D. The graph has an initial value of 60, and each successive term is determined by multiplying by 1/3 .
This denote that

Therefore, Option D best describe the expression in a simple way.