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.
--------
Question: Oxygen reacts with iron to produce rust and with hydrogen to produce water. Which statement describes both reactions?  
 (A) A different mixture is formed in each case. (B) A different solution is formed in each case. (C) Both a change of state and of elements is involved. (D) New molecules are formed but the same elements exist.

Answer: D


Question: In the forest, one type of tree produces special seeds. These seeds start to grow only after going through a fire. In the fire, the adult trees are destroyed. Which resources, needed for growth, are now available to the newly growing seeds?  
 (A) sunlight and wind (B) sunlight and space (C) soil and pollen producers (D) pollen producers and space

Answer: B


Question: Weathering causes rocks and minerals to break into smaller pieces. Which event is the best example of weathering?  
 (A) a raindrop splashing in a lake (B) a snowball rolling down a mountain (C) a river washing away soil from its bank (D) a tree root growing into the crack of a rock

Answer:
D