You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

[Q]: Adaptive characteristics that help dolphins survive life in the ocean include all of these except  
 (A) their sleek skin. (B) swimming very fast. (C) their body shape. (D) traveling alone.
[A]: D


[Q]: Forests have been cut and burned so that the land can be used to raise crops. Which consequence does this activity have on the atmosphere of Earth?  
 (A) It reduces the amount of carbon dioxide production. (B) It reduces the production of oxygen. (C) It decreases the greenhouse effect. (D) It decreases pollutants in the air.
[A]: B


[Q]: Rocks sometimes show evidence of ancient glaciers. Which is the best sign that glaciers once covered an area?  
 (A) Rocks have many scratches. (B) Rocks contain fossils. (C) Rocks are covered by moss. (D) Rocks are deep underground.
[A]:
A