Methane Drainage

Step 1: Understanding Methane Hydrates
Methane hydrates are crystalline structures in which methane molecules are trapped within water ice. These hydrates form under specific conditions of low temperature and high pressure, typically found in deep ocean floors and polar regions.
Step 2: Analyzing the Options
Option (A) is correct because methane hydrates are found near the ocean bed, where high pressure allows for their formation.
Option (B) is incorrect because methane hydrates are primarily found in ocean beds and the polar regions, not just polar regions. However, they are most abundant in ocean beds.
Option (C) is correct because methane hydrates are a potential energy source, but their release can contribute to global warming as methane is a potent greenhouse gas.
Option (D) is correct because although methane hydrates hold vast amounts of energy, the technology to extract them economically is still under development, making exploitation difficult.
Thus, the correct answers are (A), (C), and (D).