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]: Some scientists believe that the mass extinction of dinosaurs was caused by the impact of a large meteorite on Earth. This impact would have caused a darkening of the sky due to dust blown into the upper atmosphere. This darkening would have reduced the sizes of some ecosystems because of  
 (A) longer seasons. (B) accelerated erosion. (C) reduced photosynthesis. (D) increased number of hurricanes.
[A]: C


[Q]: What is the function of skin on the human body?  
 (A) Skin has pores that help the body sense odor. (B) Skin protects the body from harmful substances. (C) Skin brings oxygen directly into the body's bloodstream.
[A]: B


[Q]: Some of the thermal structure of Earth is the result of a combination of chemical composition, temperature, and pressure. Which is a boundary that best demonstrates a contact point between layers having relatively the same temperature and chemical composition?  
 (A) lithosphere and mesosphere (B) inner core and outer core (C) outer core and mantle (D) mantle and crust
[A]:
B