In which sentence is a comma used correctly?

A. Ben likes toast but, I like rolls with my meals.

B. After dinner we went to the, store to shop for shoes.

C. On Sunday I want to go to the museum, all day.

D. Oscar wants to go to the pool, so that is where we will go.
Oscar wants to go to the pool, so that is where we will go.

D. Oscar wants to go to the pool, so that is where we will go.