Option 1 is the correct answer.

Statement I states that clay layers are poor aquifers. This means that clay layers do not facilitate the flow of water easily.

Statement II states that the inter-particle space of clay minerals is the least. Clay minerals have very fine particles that are closely packed together, leaving very little space between them. This lack of space makes it difficult for water to flow through the clay layer, resulting in poor aquifer properties.

The correct explanation provided in Statement II supports Statement I by explaining the reason behind clay layers being poor aquifers. The lack of inter-particle space in clay minerals restricts the movement of water, making them less suitable for ground water storage and flow.