Infiltration is the process by which rainwater becomes ground water. So it's B. The rainwater that falls on the surface of the earth or soil
slowly gets absorbed by the soil. This process is called infiltration. The water
from outside is infiltrating the ground and mixing with the water that is already
present under the ground. It helps to soften and moist the soil of the earth
very quickly and the farmers take the advantage of sowing seeds of variety of
plants.
