The minimum size standard device box required for the installation of two $12$ AWG TW copper conductors and four $14$ AWG THHN copper conductors is a $q,?$ device box.

a$.3$ in$.2$ in$.2$ in$.$

b$.3$ in$.2$ in$.2\frac{1}{4}$ in$.$

c$.3$ in$.2$ in$.2\frac{1}{2}$ in$.$

d$.4$ in$.2\frac{1}{8}$ in$.\frac{17}{8}$ in$.$