Directions: Read the short passage given below and answer the question that follows it.
Grilling meat gives it a great flavour. This taste, though comes at a price, since the process creates free radicals which damage DNA and thus increase the eater's chances of developing colon cancer. But recent research has suggested that to find a way around this problem, one should add beer when barbecuing meat. Free radicals which form from fat and protein in the intense heat of this type of cooking can be stopped by applying chemicals called antioxidants which mop them up.
Question: The conclusion above would be more reasonably drawn if which of the following were inserted into the argument as an additional premise?