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: In a lab experiment, students are testing the identity of an unknown powder. Which method is most appropriate to move the powder to a balance?  
 (A) sweep with a brush onto transfer paper (B) scoop with lab spatula onto transfer paper (C) pinch with fingers and lift onto transfer paper (D) pour from bottle onto transfer paper

Answer: B


Question: The nucleus of the cell controls cell activity. Which body system performs a similar function in humans?  
 (A) circulatory system (B) central nervous system (C) skeletal system (D) integumentary system

Answer: B


Question: A plateau is most likely formed by  
 (A) runoff from a river. (B) weathering by waves. (C) erosion of rock debris. (D) a buildup of cooled lava.

Answer:
D