For option A, y would be the height or total growth, and x would be time or months and total height = 0.23 feet × 7.5 months
for option D, y would be the total amount of money spent and x would be the number of granola bars bought. total money spent = $0.23 × number of granola bars bought
Options B and C don't work because we don't know the initial values and an initial value would be represented in the equation.
In option E, 0.23 represents the total growth in 7 days, so it would be the total instead of the rate of change
