I have no idea what it is help pls lol

I think rainfall

Explanation:

I believe it is rainfall since it is asking how are they directly replenished which means how are themselves being refilled and since it says underground, the ocean doesn't really go underground as much as rain does since rain can literally fall anywhere inland and then go into the ground unlike the rest of these options.

are there any answer choices

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.