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.
--------
Question: Which of the following Earth layers has the greatest density?  
 (A) crust (B) mantle (C) inner core (D) outer core

Answer: C


Question: If 100 grams of vinegar and 5 grams of baking soda are poured in a container, a small amount of gas will be produced. What will the final mass of the products be if the gas is trapped in the container?  
 (A) 100 grams (B) 104 grams (C) 105 grams (D) 110 grams

Answer: C


Question: A student is investigating different types of trees. Two trees are found to have similar growth rates, temperature ranges, and sizes, but different leaves and flowers. The trees are most likely in  
 (A) the same species. (B) the same genus. (C) a different kingdom. (D) a different phylum.

Answer:
B