which material is an aquifer layer most likely made of? soil clay solid granite cracked rocks

Brief Explanations:

An aquifer is a permeable rock layer that can store and transmit water. Cracked rocks have spaces (fractures) that allow water to move through and be stored. Soil has some porosity but may not have high - enough permeability compared to cracked rocks in many cases. Clay is impermeable as its particles are very fine and tightly packed. Solid granite has low porosity and permeability.

Answer:

D. cracked rocks