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 d. in fact i donated your old, outdated clothes.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! :)

The answer is exciting networking.