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.

Which of the following best describes an advantage of using a mass production manufacturing system instead of a custom manufacturing system?  
 (A) Customers can provide specific feedback to workers. (B) Workers become skilled in all aspects of assembly. (C) Goods can be easily modified for customers. (D) Products can be made at a lower cost.
D

Which is a process that occurs during photosynthesis?  
 (A) Plants take in oxygen and release sugar. (B) Plants take in sugar and release minerals. (C) Plants take in minerals and release carbon dioxide. (D) Plants take in carbon dioxide and release oxygen.
D

Which property is thought to characterize objects in the Oort Cloud?  
 (A) They are composed mostly of iron. (B) They are composed mostly of ice. (C) They regularly revolve near the Sun. (D) They regularly replenish water on Earth.

B