Answer:
C. Water on alternate days.
Explanation:
As the explanation says, in the oais in the Sahara Desert there are strong efforts to keep the water that they have, and this efforts include not wasting water on plants that do not need it, sometimes we can over-water plants and the excess of water just gets evaporated into the environment, palm trees only need to be watered every other day, that´s why they are only watered on alternate days.
