When separating items in a list, a writer should- end the list with a colon. separate the items with colons. add a comma after the “and” before the last item. add a comma before the “and” before the last item.

The correct answer is D.

The correct way to separate items in a list is to add a comma before the "and" that is placed before the last item of the list.

Answer A is wrong because the list should start with a colon rather than end with it.

Answer B is not correct either becase items are separated with commas, not with colons.

And answer C is also incorrect because the comma should be placed before the "and" and not after it.

Add the comma before the "and" before the last item.

Ex.

In the yard there were toys, a car, and firewood.