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.

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.
A

A student pushed a large rubber ball on a flat, frictionless surface. The ball rolled at a speed of 1 meter per second. Which statement best describes the motion of the ball when the student stopped pushing the ball?
(A) The ball accelerated. (B) The ball did not move. (C) The ball changed direction. (D) The ball continued to move in the same direction.
D

Alan is using cabbage juice to determine the relative pH of various household solutions. Which of these steps communicates the results of his investigation?
(A) Conduct multiple trials (B) Write down a procedure (C) Identify the materials to be tested (D) Record observations and data in a journal
D