The line in the chart in slope intercept form has the equation
y = 25x + 50
Since x is the number of days and y is the total cost, it looks like the rental cost is a linear function of the number of days you've rented the game. So the most logical response is that the rate of change represents "daily rate for renting the game"
Since the actual options from the "drop-down menu" weren't provided, you'll have to select the choice that most closely matches the intent of "daily rate for renting the game"
