which material is an aquifer layer most likely made of?\nsoil\nclay\nsolid granite\ncracked 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 flow through and be stored, making them a likely material for an aquifer layer. Soil has smaller pores and may not transmit water as efficiently as cracked rocks in large - scale aquifer systems. Clay has very small pores and is relatively impermeable. Solid granite is impermeable without fractures.

Answer:

D. cracked rocks