The correct answer is D. In 2008, more than one million American students gave nearly 20 million service hours to their communities.
Explanation:
In texts, including articles the introduction is commonly the first paragraph in a text that introduces or presents the general topic and the point or points that will be explained during the text. Besides this, it is common the first sentence of an introduction includes a quote, a question, a piece of statistical information or a strong statement that acts as a "hook" catching the readers attention.
Considering this, in the case of the article presented the sentence that beings the introduction is "In 2008, more than one million American students gave nearly 20 million service hours to their communities" because this is the first sentence in the text and therefore the first sentence in the introduction, besides this, the sentence presents statistical information that as a "hook" for readers and introduces or presents the main topic that is volunteer service.
Answer:
The boy who solved the puzzle was praised by the teacher.
