According to the Darcy-Weisbach equation for head loss due to pipe friction:

Since the two pipes are similar (identical friction factor $f$, length $L$, and diameter $D$), the head loss is directly proportional to the square of flow velocity ($h_f \propto V^2$):

Surface tension is caused by intermolecular cohesive forces in the liquid. In the bulk liquid, molecules experience balanced attractive forces in all directions. At the liquid-gas interface, surface molecules experience an unbalanced inward net attraction towards the bulk, creating tension. Thus, increasing the surface area requires work against these cohesive attractive forces. Both (A) and (R) are true, and (R) is the correct explanation of (A).

Classification of fluid flow in hydraulics:
Steady flow: Flow parameters (velocity, depth) do not change with time at any given cross-section ($\partial V/\partial t = 0, \partial y/\partial t = 0$) -> (III).
Uniform flow: Flow parameters (velocity, depth) do not change along the length/space at any given instant ($\partial V/\partial s = 0$) -> (IV).
Non-uniform flow: Velocity changes from point to point along the length of flow ($\partial V/\partial s \ne 0$) -> (I).
Unsteady flow: Velocity and depth change with time at a given cross-section ($\partial V/\partial t \ne 0$) -> (II).