Which sentence does not contain any errors in comma usage?

a.
before we go to the grocery store each weekend, we check to see how empty the refrigerator is.

b.
yes i want to hear the entire story.

c.
at grocery stores, on the weekends, express lines are usually fastest.

d.
reading in the car can, instantly make me feel nauseous.

what gradee ya in so we can do it im 8th grade

                                                        -hannahsgachagal

                                                          (p.s thats my real you tube lol)

put the trash into the back of the truck and drive the truck to the back. then you must unload the truck.