2015 AMC 12A Problem 1

Inside the parentheses, $$\begin{aligned} &2^0-1+5^2+0 \\ &\quad = 1-1+25+0 = 25. \end{aligned}$$ Then $$(25)^{-1}\times 5 = \dfrac{5}{25} = \dfrac{1}{5}.$$ Thus, the correct answer is C.