1% of 1% of 25% 1000 is:

Answer: Option A

$$\begin{array}{rl}& 1\%\text{of}1\%\text{of}25\%1000\\ & =1\%\text{of}1\%\text{of}\frac{25\times 1000}{100}\\ & =1\%\text{of}1\%\text{of}250\\ & =1\%\text{of}\frac{1\times 200}{100}\\ & =1\%\text{of}2.5\\ & =\frac{2.5}{100}\\ & =0.025\end{array}$$