The answer is D. Forrest succession
This is because the rate at which the trees grew is not given so we can't accurately say it is a rapid change. Human impact couldn't be correct because it never said humans had anything to do with it. Extinction means a large group of living things or a species dies off so that couldn't be correct either. The forest growing large trees is a successful growth of a forest. Therefore, it must be D.
Hope this helped!
