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]: Which of these tools is best for recording observations outdoors?  
 (A) a ruler (B) a graph (C) a notebook (D) a calculator
[A]: C


[Q]: What determines how long the Moon takes to complete one cycle of phases?  
 (A) the period of rotation of the Moon around its axis (B) the period of revolution of the Moon around Earth (C) the period of rotation of Earth around its axis (D) the period of revolution of Earth around the Sun
[A]: B


[Q]: The rover Spirit is a robotic probe that NASA has placed on Mars. The gravitational attraction of Mars is approximately 62% less than that of Earth. Compared to its measurements on Earth, on Mars the probe has  
 (A) the same weight and the same mass. (B) a larger weight, but smaller mass. (C) a smaller mass and larger weight. (D) a smaller weight and the same mass.
[A]:
D