TASK DEFINITION: You are given a science question (hard-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.
PROBLEM: Tobias rode his bike on a road for a 2 hr period. On average, he passed a 1 km marker every 3 min during this period. Which of the following was his average speed for this 2 hr period?
(A) 10 km/hr (B) 15 km/hr (C) 20 km/hr (D) 25 km/hr

SOLUTION: C

PROBLEM: Which invention would a culture living above the Arctic Circle most likely develop?
(A) ice production (B) air conditioning (C) insulated clothing (D) irrigation canals

SOLUTION: C

PROBLEM: Which of these reduces the need for people to use nonrenewable resources?
(A) recycling paper products (B) watering the lawn once a week (C) designing cars that are fuel efficient (D) using coal to generate electricity

SOLUTION:
C