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.

A student conducts an investigation using mold spores. In one part of the investigation, he needs to closely examine a spore sample. Which piece of equipment does the student need to use to keep mold spores from entering his respiratory system?  
 (A) breathing mask (B) safety goggles (C) rubber gloves (D) lead smock
A

What is the function of skin on the human body?  
 (A) Skin has pores that help the body sense odor. (B) Skin protects the body from harmful substances. (C) Skin brings oxygen directly into the body's bloodstream.
B

The electrical charge of the nucleus of an atom is +12. How many electrons does the atom have in its neutral state?  
 (A) 6 (B) 12 (C) 18 (D) 24

B