To evaluate \((2/5)^{-3}\), we can use the property of exponents that states \(a^{-n} = \frac{1}{a^n}\). Hence, we have:
\[ (2/5)^{-3} = \frac{1}{(2/5)^3} \]
Next, we need to calculate \((2/5)^3\):
\[ (2/5)^3 = \frac{2^3}{5^3} = \frac{8}{125} \]
Now substituting back into our expression, we get:
\[ (2/5)^{-3} = \frac{1}{(2/5)^3} = \frac{1}{\frac{8}{125}} = \frac{125}{8} \]
Thus, the value of \((2/5)^{-3}\) is:
\[ \boxed{125/8} \]
So, the correct answer from the options is D. 125/8.