Which sentence does not contain any errors in comma usage? A. The dog for instance, loves to eat my cooking. B. By the way, I still love to watch cartoons. C. It's already five o'clock at any rate. D. In fact I donated your old, outdated clothes.
That would be B. It gives a fragment and introduction (some sort of phrase), then continues with the sentence. I can also tell it's used correctly by this trick: If you put what's written before the comma at the back of the sentence, it should still make sense- And it does! :)
