Answer:
B
Explanation:
Rate of change states

They are asking from day 2 to day 5, making 2 and 5 our x1 and x2.
On the table, the number below 2 is 0.75. The number below 5 is 2.5. We can use these as y1 and y2.
Now we can plug it in

0.6 because it asks for approximate