instruction:
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.
question:
The human immunodeficiency virus (HIV) causes AIDS. The first known human cases AIDS were in Africa in the late 1950s. Since then, tens of millions of people have died from the disease, and tens of millions more people all over the world are infected. Which term best describes the disease AIDS?  
 (A) isolated cases (B) outbreak (C) epidemic (D) pandemic
answer:
D


question:
Which is a way the agricultural biotechnology industry could have a positive impact on the environment?  
 (A) by producing crops that are virus resistant (B) by making robots to replace large farm machines (C) by reducing the need for countries to import food (D) by increasing the use of wind farms that produce electricity
answer:
C


question:
Which action should be taken in order to identify the streak of a mineral during an investigation?  
 (A) Weigh the mineral (B) Dip the mineral in acid (C) Heat the mineral until it melts (D) Drag an edge of the mineral across a tile
answer:

D