Infiltration is the process by which rainwater becomes
a. river water.
b. saltwater.
c. groundwater.
d. ocean water.

C. Groundwater

 Infiltration is the process by which rainwater becomes groundwater. Through this process the water on the ground surface enters the soil. Infiltration rate is a measure of the rate at which soil can absorb rainfall or irrigation. It is measured in inches per hour or millimeters per hour and it decreases as the soil saturated. Infiltration is governed by two forces, gravity and capillary action. The rate of infiltration can be observed through the characteristics of the soil.

Then it is june the conclusion to the second sentence is just restating "if it is june then it is summer"