So you need to compute all the rates to see which is the best deal.
$1.79/12.5ft^2=$0.1432 per ft^2
$5.29/40ft^2=$0.13225 per ft^2
$8.49/50ft^2=$0.1698 per ft^2
$6/60ft^2=$0.10 per ft^2
So the last option is the cheapes per square foot and thus is the best deal. Ordered from least to greatest.
Sherbert, blue, red, and green
Rate of change refers to moving a certain amount of distance over a certain time period
rate of change= velocity in this case.
Answer:
you might want to do more reseearch but to me it looks like c