An alternating voltage is represented as $\mathrm{E}=20\sin 300\mathrm{t}.$ The average value of voltage over one cycle will be 

• A

  Zero 

• B

  10 volt

• C

  $20\sqrt{2}\mathrm{volt}$

• D

  $\frac{20}{\sqrt{2}}\mathrm{volt}$