Gilbert is training for a bike race. As part of his training, he does practice rides on portions of the actual race course. Gilbert's first practice ride covers 5 miles of the course, and his second practice ride covers 9 miles of the course. Between these practice rides, he increase his average speed by 2 miles/hour. The denominator of the function that models practice ride 2 represent the: A . Increase in Gilbert’s average biking speed B. Distance Gilbert’s travels C . Time it takes Gilbert’s to travel 5 miles D . Biking speed for the second practice ride .
