How stagnation point on the topside of the airfoil reaches the trailing edge?

A)
Due to drag forces
B)
Due to surface forces
C)
Due to viscous forces
D)
Due to pressure forces

Correct Answer :   Due to viscous forces


Explanation : The stagnation point on the topside of the airfoil then moves until it reaches the trailing edge. The starting vortex eventually dissipates due to viscous forces. As the airfoil continues on its way, there is a stagnation point at the trailing edge. The flow over the topside of the airfoil conforms to the upper surface of the airfoil.