Luke summarized the causes of earthquakes with the following sentence. Earthquakes have both natural causes like volcanoes, faults and landslides and human made causes like mining explosions, nuclear testing and tectonic plate subduction. What needs to be corrected?

Punctuation.

Explanation:

The sentence is very confusing when first read due to lack of proper punctuation. We know earthquakes have two things because the writer says, "have both". However, a sequence of explanations and examples are put between those two things, without any punctuation to separate them, which makes it harder to understand. What are the two things earthquakes have? Natural cause and human-made causes. What are volcanoes, faults and landslides? Examples of natural causes. What are explosions, nuclear testing and tectonic plate subduction? Examples of human-made causes.

Now, let's add punctuation that will help make the information above clear:

uh, the answer is d i guess.

i believe the answer is a