The Expected Value, E(X), of a Uniform Random Variable X $a \leq x \leq b$

The expected value, E(X), of a uniform random variable X defined over the interval $a \leq x \leq b$ , is: $\begin{array}{|l|l|}\hline\text { A. } & a+b \\\hline \text { B. } & a-b \\\hline \text { C. } & (a+b) / 2 \\\hline \text { D. } & (a-b) / 2 \\\hline\end{array}$