Task: Question Answering
Input (English): Question: The urea cycle: 
 Options:  <1> It involves the degradation of urea. <2> It was proposed by Hatch and Slack. <3> It contains a reaction that transforms citrulline into ornithine. <4> It is intimately linked to glycolysis. <5> It begins with the formation of carbamylphosphate.
Output (English): 5