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.

[EX Q]: Emily made a cup of tea and stirred it with a spoon. The spoon became warm. How was the heat from the tea transferred to the spoon?  
 (A) convection (B) radiation (C) conduction (D) evaporation
[EX A]: C

[EX Q]: A chameleon can change colors to match its surroundings. This ability helps the chameleon survive because it can  
 (A) stay warm. (B) find a mate. (C) hunt for food. (D) be easily seen.
[EX A]: C

[EX Q]: 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
[EX A]:
C