For a circular sewer running partially full, the proportionate wetted perimeter is given by:

• A. \(\frac{p}{P}=\frac{D}{4}\)
• B. \(\frac{p}{P}=\frac{\alpha}{360^0 }\)
• C. \(\frac{p}{P}=\frac{\alpha}{\pi D}\)
• D. \(\frac{p}{P}=\frac{\alpha}{180^o}\)