Task: Question Answering
Input (English): Scientists determined that cabbages grown using Fertilizer A grew bigger than cabbages grown using Fertilizer B or no fertilizer at all. The scientists repeated the investigation and produced the same results. Which best explains the purpose of repeating this investigation?  
 (A) to ensure that the cabbages are safe for human consumption (B) to discover the scientific principle that causes the increased growth (C) to confirm that the observed differences were caused by the fertilizer (D) to determine the difference between the experimental and control groups
Output (English): C