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]: Which land feature is formed from erosion by waves?   
 (A) a sandbar (B) a sea cliff (C) a barrier reef (D) a barrier island
[EX A]: B

[EX Q]: Which tool is best used to collect information about the weather?  
 (A) ruler (B) stopwatch (C) thermometer (D) collecting net
[EX A]: C

[EX Q]: Which invention will best help people travel quickly to far away places?  
 (A) car (B) boat (C) airplane (D) skateboard
[EX A]:
C