Answer:
Option (D)
Explanation:
Historical geology usually refers to the study of the changes and the variation that occurs at or below the surface of the earth. In simple words, it mainly involves the study of past events. This includes the variation and evolution of different life forms that existed on earth over a time of about 3.8 billion years until the present. It basically comprises the important part of geology namely Paleoclimatology, Paleontology and Paleoseismology. This historical geology is also known as Paleogeology.
Thus, historical geology involves the biological changes that occur over a definite time.
Thus, the correct answer is option (D).
The answer is: [A]: troposphere .
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