ANS:B - maximum

The velocity of the fluid particle at the center of the pipe section is maximum. In a fully developed flow within a pipe, where the flow is assumed to be steady and turbulent effects are negligible, the velocity profile typically exhibits a parabolic shape. This means that the velocity is highest at the center of the pipe and gradually decreases to zero at the pipe walls due to the no-slip condition. The no-slip condition implies that the fluid particles in contact with the pipe walls have zero velocity relative to the wall. As we move away from the walls towards the center of the pipe, the velocity of the fluid particles increases, reaching its maximum at the centerline of the pipe. Therefore, the velocity of the fluid particle at the center of the pipe section is maximum.