For how many (not necessarily positive) integer values of n is the value of 4000 \cdot\left(\dfrac{2}{5}\right)^{n} an integer?

**Answer Choices**

A. 3

B. 4

C. 6

D. 8

E. 9

For how many (not necessarily positive) integer values of n is the value of 4000 \cdot\left(\dfrac{2}{5}\right)^{n} an integer?

**Answer Choices**

A. 3

B. 4

C. 6

D. 8

E. 9