The structure of the passage is mainly the format "chronology" as they describe the growth of the pine trees in "years of age." So, chronology is the correct answer.
Expository writing is a type of writing in a process of order in a chronological way that;
When employing chronological order, but the events (pine tree growth) in the order in which they occurred, or will occur if you're giving directions.
Therefore, chronology is the correct structure of the passage.
Check out the link below to learn more about the Chronological text;
https://brainly.com/question/14266510
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