Question

what is the main challenge in using wind energy? ; ttent availability; limited supply; high cost of production; environmental pollution

Explanation:

Wind energy's main challenge is intermittent availability (wind isn't always blowing steadily), so the green option (assuming the first is "Intermittent availability") is correct. "Limited supply" is wrong (wind is renewable/unlimited in nature), "High cost of production" is less a main challenge now with tech advances, and "Environmental pollution" is incorrect as wind energy is clean.

Answer:

(Assuming the first option is "Intermittent availability") A. Intermittent availability