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.

[Q]: A radio station broadcasting across a large area is experiencing thunderstorms. How will the radio waves from the station be affected?  
 (A) wavelength will be increased (B) amplitude will be unchanged (C) frequency will be distorted (D) speed will be decreased
[A]: C


[Q]: Which material is most easily recycled at school?  
 (A) plastic wrap (B) notebook paper (C) ice cream sticks (D) rubber erasers
[A]: B


[Q]: Which of the following eras is known as the "Age of Mammals"?  
 (A) Precambrian (B) Paleozoic (C) Mesozoic (D) Cenozoic
[A]:
D