Which sentence best shows correct comma usage?
a .what would you like ken, for breakfast?
b. what would you like, ken, for breakfast?
c. what would, you like ken, for breakfast?
d. what would you like, ken for breakfast?

The sentence that best shows correct comma usage is, indeed, letter B) What would you like, Ken, for breakfast?

Explanation:

As we can see, the sentences in letter A - D are actually the same sentence with different punctuation. This sentence comes with a name right in its center: Ken. However, the speaker is not talking about Ken. The speaker is talking to Ken, addressing him, asking Ken a question. In that case, we have what is called a vocative - a word or phrase employed to address someone directly.

A vocative must always be set off by commas. If, for example, it had come at the beginning of the sentence, "Ken" would be followed by just one comma. But, since it came in the middle of the sentence, it needs a comma right before it, and another one right after it. Thus, the best option is letter B:

What would you like, Ken, for breakfast?

Another example with a vocative in the middle of the sentence would be:

- What do you think, doctor, of these results?

go

explanation:

because it can't be a slow, i would say possibly whoa, but there's nothing too surprising about orange juice, and because it tastes awesome it's a go drink, not food.