You find a leaf that has large stomata and a thick, waxy covering. what is clear about the original plant

The answer would be: The plant minimizes water loss.

Water is an important resource for plants, especially in dry condition. Stomata function is to allow gas exchange, but it could also allow the plants to lose water. Stomata allow the plants to take carbon dioxide from the atmosphere. The waxy covering will prevent the unwanted water loss from the stomata.