Select the best answer from the choices list. The answer should be the index of the correct choice (starting from 0).

Question: How long is a hiking trail?      
Choices: [0: '6 centimeters', 1: '6 kilometers']      
Answer: 1      
Explanation: The better estimate for the length of a hiking trail is 6 kilometers.
6 centimeters is too short.

Question: How long is a hiking trail?
Choices: [0: '4 meters', 1: '4 millimeters', 2: '4 kilometers', 3: '4 centimeters']
Answer: 