Answer:
third
Explanation:
The utility for consuming the first donut is 9 utils.
The utility for consuming the second donut is the difference from the total utility for the first two and just the first donut.
[tex]U_2 = 19-9 = 10\ utils[/tex]
The utility for consuming the third donut is the difference from the total utility for the first three and just the first two donuts.
[tex]U_3 = 30-19 =11\ utils[/tex]
The utility for consuming the fourth donut is the difference from the total utility for the first four and just the first three donuts.
[tex]U_4 = 38-30 =8\ utils[/tex]
Since the utility for the 4th donut is less than the utility for the 3rd donut, utility begins to diminish after consuming the third donut.
