Where two $12-3$ with ground AC cables $($with external connectors$)$ are installed, what is the smallest metal box listed below that can be used for a box containing a duplex receptacle?

Select one:

a$.$

$3"2"21/4"$ device box

b$.$

$4"21/8"21/8"$ device box

c$.$

$3"2"31/2"$ device box

d$.$

$33/4"2"21/2"$ masonry box

e$.$

None of these is large enough$+$