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: What property is the same for each atom of an element?  
 (A) energy (B) mass number (C) atomic number (D) number of neutrons

Answer: C


Question: Some plant species are more tolerant of acidic soil than others. The tolerant species are favored in areas affected by which consequence of human activity?  
 (A) mixing of pollutants with rain (B) erosion of topsoil by clearcutting (C) runoff of fertilizer used in farming (D) thinning of the atmospheric ozone layer

Answer: A


Question: Norma's flashlight was not working. She replaced the old batteries with new ones, and the flashlight turned on. Why did the flashlight work after she replaced the batteries?  
 (A) because the batteries conduct the electricity (B) because the batteries supply the energy (C) because the batteries produce light (D) because the batteries produce heat

Answer:
B