Question

Which sentence correctly uses commas to separate items in a list? The Library of Congress is home to the world's most extensive comic-book collection, oldest original newspaper collection and, most abundant collection of cartographic items. The Library of Congress is home to the world's most extensive comic-book collection oldest original newspaper collection and most abundant collection of cartographic items. The Library of Congress is home to the world's most extensive comic-book collection, oldest original newspaper collection, and most abundant collection of cartographic items. The Library of Congress is home to the world's most extensive comic-book collection, oldest original newspaper collection and most abundant collection of cartographic items.

Answer 1

It's the third one!

The only one that uses the commas correctly is the third sentence. The comma must go before the coordinating conjunction.