In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". 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.

Example input: Article: Homework can put you in a bad mood , and that might actually be a good thing. Researchers from the University of Plymouth in England doubted whether mood might affect the way kids learn. To find out the answer, they did two experiments with children. The first experiment tested 30 kids. Someshapes were hidden inside a different, larger picture. The kids had to find the small shapes while sitting in a room with either cheerful or sad music playing in the background. To test their mood, the scientists asked the kids to point to one of five faces, from happy to sad. Children who listened to cheerful music tended to point to the smiley faces while the others pointed to the unhappy ones. The researchers found that sad kids took at least a second less to find the small shapes. They also found an average of three or four more shapes. In the second experiment, 61 children watched one of two scenes from a film. One scene was happy, and the other was sad. Just like in the first experiment, kids who saw the sad scene acted better compared to the others. The researchers guessed that feeling down makes people more likely to focus on a problem or difficult situation. Not all scientists agree with them, however. Other studies argued that maybe, that cheerful music in the first experiment distracted kids from finding shapes. While scientists work on finding out the answers, it still might be wise to choose when to do your tasks according to your mood. After eating a delicious ice cream, for example, write an essay.
Question: Researchers did experiments on kids in order to find out _ .
Options: (A) how they really feel when they are learning (B) whether mood affects their learning ability (C) what methods are easy for kids to learn (D) the relationship between sadness and happiness
Example output: B
Example explanation: It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment. So, B is the correct answer.
Q: Article: Get ready to cycle your heart out at these local and overseas destinations perfect for cycling. 1. Amsterdam, The Netherlands. With more bikes than people, the city has a large number of cyclists. Low speed limits in the centre control the impact of cars, while bike racks( ) on public transport make it easy to travel long distances. You can also find rental shops everywhere. 2. Berlin, Germany. With over 1000 km of bike paths, the vast majority of which are protected lanes, it's no wonder Berliners love to get around by bike. For the traveller, the major sights are within easy reach on a bicycle. The "Call A Bike" share system allows you to simply lock the bike to any fixed object and call in a code to return it. 3. Paris, France. Home to the Velib' public bike sharing system that has over 20, 000 bikes, and with 500km of bike paths, Paris cyclists can enjoy the city safe from motorists. A Velib' station is almost always within sight, or just around the next corner. 4. Tokyo, Japan. Despite being home to one of the most developed public transportation networks on the planet, Tokyo residents still cycle in large numbers. Though the extent of bike lanes is limited, safe drivers ease the tension between car and cyclist. Unique automatic underground bike parking garages are provided when you need to store your bicycle. 5. Perth, Australia. A large part of Perth's intelligent basic facilities are made up of bike paths, which allow commuters to get into and around their city with ease. There are free bike lockers and racks across the city. For the visitor, numerous scenic routes line the coastline and the local Swan River.
Question: In which country can you find the "Call A Bike" system?
Options: (A) The Netherlands. (B) France. (C) Germany. (D) Australia.
A:
C