You are given a science question (easy-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]: Which of the following is closest to the percentage of the total water on earth that is freshwater?  
 (A) 100% (B) 90% (C) 70% (D) 3%
[A]: D


[Q]: The incompleteness of the fossil record results primarily from which phenomenon?  
 (A) the frequency and irregular timing of organism speciations (B) the metamorphosis of most sedimentary rock by heat and pressure (C) the geologically rapid cycling of crust material back into the mantle (D) the rarity with which organic remains are exposed to fossil-forming conditions
[A]: D


[Q]: Which unit is used to indicate the amount of energy in food?  
 (A) ounce (B) degree (C) calorie (D) gram
[A]:
C