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.

[EX Q]: A movie studio will use two methods of communication, television and the Internet, to advertise a new movie. Which of the following must both methods of communication use in order to show the advertisements to viewers around the world?  
 (A) systems to locate viewers (B) networks to transmit signals (C) printing to create the images (D) software to search for images
[EX A]: B

[EX Q]: What type of galaxy is the Milky Way?  
 (A) spiral (B) elliptical (C) irregular (D) oval
[EX A]: A

[EX Q]: Which of these would best be shown as a 3-D model?  
 (A) color spectrum (B) magnetic field (C) skeletal system (D) water cycle
[EX A]:
C