Definition: 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.
Input: Which of the following devices relies on electromagnetic radiation in the radio wave region of the spectrum for operation?
(A) sun tanning lamp (B) electric light bulb (C) cellular telephone (D) electric toaster
Output:
C