I'm not sure if you meant to label the table C instead of B, so... this table:
x y
1 4
2 2
3 4/3
4 1
...shows a negative, or decreasing, rate.
This is because the x-axis usually represents time and we can see that as x (time) increases, y (an amount of something) is getting lower each time.
4 > 2 > 4/3 (1 1/3) > 1
