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.

[EX Q]: A person cuts down a living oak tree. The person burns the wood from the oak tree to boil water. Which sequence correctly orders the energy transformations that occurred from the living tree to the boiling of water?
(A) light energy chemical energy thermal energy (B) thermal energy chemical energy light energy (C) chemical energy mechanical energy electrical energy (D) electrical energy mechanical energy chemical energy
[EX A]: A

[EX Q]: Sound is able to travel faster in solids than in air because the molecules in a solid are
(A) closer together than air molecules. (B) more easily moved than air molecules. (C) moving faster than air molecules. (D) larger than air molecules.
[EX A]: A

[EX Q]: A student is shown a slide of cells from a species of producer in a food web. The student observes that the cells have chloroplasts. What conclusion about the food web is best supported by these findings?
(A) The producers capture energy from sunlight. (B) The food web is found in a terrestrial ecosystem. (C) The producers in the web are single-celled organisms. (D) The food web contains many herbivores and omnivores.
[EX A]:
A