challenge: How did boats qualify for the final in the Women's K-4 500 metres Canoeing event at the 2012 Summer Olympics?
  
  A. The first boat and second-best in each heat qualified for the final, with the remainder going to the semi-final where the top five boats then qualified for the final
  B. The first boat in each heat qualified directly for the final, and the second-best boat in each heat went to the semi-final
  C. The top two boats in each heat qualified directly for the final, while the rest were eliminated
  D. All boats competed in the semi-final, and the top eight boats then qualified for the final
  Answer: 