Half percent, written as a decimal, is

Answer: Option C

$$\begin{array}{rl}& \text{As}\text{we}\text{know},1\%=\frac{1}{100}\\ & \text{Hence},\\ & \frac{1}{2}\%=\frac{1}{2}\times \frac{1}{100}\\ & =\frac{1}{200}\\ & =0.005\end{array}$$