While calculating bearing capacity for a foundation, the water table is likely to permanently remain at a level of 20 m for a square foundation of side 5 m , then the correction factor for water table will be taken as:

Correct option is A

In bearing capacity calculations, the water table correction factor depends on the position of the water table relative to the foundation base and its width.
For a square foundation of side 5 m, the zone of influence of the water table is approximately up to a depth of about one foundation width (≈ 5 m) below the base.
Given that the water table is permanently at 20 m, it lies well below the zone of influence.
Hence, the presence of the water table does not affect the bearing capacity, and no correction is required.
Water table correction factor = 1.00