The value of the integral\(\mathop \oint \nolimits_s \vec r.\vec n\;ds\)over the closed surface S bounding a volume V, where \(\vec r = x i + y j + z k\) is the position vector and n̂ is normal to the surface S, is

• A. V
• B. 2V
• C. 3V
• D. 4V