A study published by Rice University geoscientist Ming Tang in 2019 offers a new explanation for the origin of Ea __ structures called arcs, towering ridges that form when a dense oceanic plate subducts under a less dense continental plate, melts in the mantle below, and then rises and bursts through the continental crust above. Which choice completes the text so that it conforms to the conventions of Standard English? A. continents geological B. continents: geological C. continents; geological D. continents. Geological

## Step 1<br />The problem is a punctuation question, which is a common type of question in English language and literature. The task is to choose the correct punctuation to complete the sentence in a way that conforms to the conventions of Standard English.<br /><br />## Step 2<br />The sentence is discussing the origin of certain geological structures called arcs. The sentence is divided into two parts: the first part describes the process of how these structures form, and the second part provides additional information about these structures.<br /><br />## Step 3<br />The second part of the sentence is providing additional information about the structures, which is a list of geological terms. This list is not a continuation of the first part of the sentence, but rather a separate piece of information.<br /><br />## Step 4<br />In English grammar, a colon is used to introduce a list, a quote, an explanation, or an example. In this case, the colon is used to introduce a list of geological terms.