Q: You are presented with the quiz "What can cause harm to humans?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "insect bites cause harm to living things" and "some assassin bug bites can cause an allergic, life-threatening reaction in humans". So, what's the best answer to the question?

OPTIONS:
[1]. cigarettes
[2]. viruses
[3]. steroids
[4]. air molecules
[5]. assassin bugs
[6]. vegetables
[7]. ladybugs
[8]. smoking tobacco
A:
[5].