Answer:
B. [tex] \frac{17}{72}[/tex]
Step-by-step explanation:
[tex] {a}^{2} + {b}^{3} \\ \\ = \bigg( \frac{1}{3} \bigg)^{2} + \bigg( \frac{1}{2} \bigg)^{3} \\ \\ = \frac{1}{9} + \frac{1}{8} \\ \\ = \frac{8 + 9}{9 \times 8} \\ \\ = \frac{17}{72} \\ [/tex]