Most of Western music since the Renaissance has been based on a seven-note scale known as the diatonic scale, but when did the scale originate? A fragment of a bone flute excavated at a Neanderthal campsite has four holes, which are spaced in exactly the right way for playing the third through sixth notes of a diatonic scale. The entire flute must surely have had more holes, and the flute was made from a bone that was long enough for these additional holes to have allowed a complete diatonic scale to be played. Therefore, the Neanderthals who made the flute probably used a diatonic musical scale.

In the argument given, the two portions in boldface play which of the following roles?

• AThe first introduces evidence to support the main conclusion of the argument; the second is the main conclusion stated in the argument.  
• BThe first introduces evidence to support the main conclusion of the argument; the second presents a position to which the argument is opposed.  
• CThe first describes a discovery as undermining the position against which the argument as a whole is directed; the second states the main conclusion of the argument.  
• DThe first introduces the phenomenon that the argument as a whole seeks to explain; the second presents a position to which the argument is opposed.  
• EThe first introduces the phenomenon that the argument as a whole seeks to explain; the second gives a reason to rule out one possible explanation.