We'll try to eliminate the wrong options
- when $k = 4, \dfrac{(4 + 2)^2}{4 - 3} = 36$ (integer)
- when $k = 8, \dfrac{(8 + 2)^2}{8 - 3}$ = $\dfrac{100}{5} = 20$ (integer)
- when $k = 10, \dfrac{(10 + 2)^2}{10 - 3}$ = $\dfrac{144}{7} = 20.57$ (not an integer)
- when $k = 16, \dfrac{(16 + 2)^2}{16 - 3}$ = $\dfrac{324}{13} = 24.92$ (not an integer)
- when $k = 18, \dfrac{(18 + 2)^2}{18 - 3}$ = $\dfrac{400}{15} = 26.66$ (not an integer)
- when $k = 26, \dfrac{(26 + 2)^2}{26 - 3}$ = $\dfrac{784}{23} = 34.08$ (not an integer)
- when $k = 28, \dfrac{(28 + 2)^2}{28 - 3}$ = $\dfrac{900}{25} = 36$ (integer)
Correct option (C) 4, 8, 28