For a sphere that is dropped into a viscous liquid, Strokes law states that the force of friction is given by

• A. (6π × radius of the sphere × coefficient of viscosity) ⁄ velocity of the sphere
• B. 6π × radius of the sphere × coefficient of viscosity × velocity of the sphere a
• C. 6π ⁄ (radius of the sphere × coefficient of viscosity × velocity of the sphere
• D. (6π × radius of the sphere) ⁄ (coefficient of viscosity × velocity of the spher