Joshua, with his members, . . . . . . . . really well.

Answer: Option D

Among the following options, 'D' is the correct one.
So, the complete sentence is- Joshua, with his members, sings really well.
Here, Joshua is the singular number and it is followed by 'with his members'.
The subject is parted from the verb by 'with his members'.
So,'s' is added to the verb 'sing'.
Another example- "He with all his puppies, stays near my house."