The tube shown is of uniform cross-section. Liquid flows through it at a constant speed in the direction shown by the arrow. The liquid exerts on the tube 

• Due to the fluid's change in momentum over time, v(dm/dt), force will be generated.
• The liquid applies forces at the bends. (The liquid experiences a change in momentum at these locations; as a result, the liquid and tube experience forces from one another.) 
• Together, the two forces produce a clockwise torque.

Hence the correct answer is a clockwise to torque.