ANS:C -

In a horizontal circular pipe under steady-state fluid flow conditions, the nature of shear stress distribution along the cross-section is typically parabolic. This means that the shear stress is maximum at the pipe wall (due to the no-slip condition) and decreases linearly towards the center of the pipe. At the center of the pipe, the shear stress is theoretically zero. This parabolic distribution of shear stress arises due to the velocity profile of the fluid flow, which is typically laminar near the pipe wall and becomes more uniform towards the center of the pipe under laminar flow conditions.