20. According to the article, how has observing the decline of big trees most affected the author?

O A He became active in reducing carbon emissions in

order to protect big trees.

B He expanded his previous research of American big

trees to become a global study.

C He expanded his research, intending to further explain

and publicize the causes of big trees' decline.

D He was relieved and encouraged by people's

enthusiasm to protect big trees and the environment.

C. He expanded his research, intending to further explain and publicize the causes of big trees' decline.

Explanation:

The author of the article is concerned about the decline of large trees around the world and fears that this type of trees will cease to exist over the years. Because of this concern, he decided to disclose the causes of this decline, to educate the population about what is happening and to mobilize people in favor of these trees. In this article, he shows that the research on this decline has been expanded to show that in addition to deforestation and environmental exposure, there is a biological issue that leaves these trees more fragile and in need of care.

i need more details

explanation:

600 dollars if i'm not mistaken.