TEAS English and Language Usage Practice Test

The sentence "I bought apples, oranges, and bananas." is correctly punctuated because it properly uses commas to separate items in a list. The use of commas before and between each item helps clarify that these are distinct objects being referred to. Including the comma before "and" — known as the Oxford comma — is optional in many styles, but it enhances clarity and avoids ambiguity, especially in complex lists. In this case, it makes it clear that the items are separate suggestions being purchased.

The other choices do not meet the standard rules for punctuation in lists. For example, omitting the commas creates confusion in options where it should be clear that each item is individual, and an erroneous placement of a comma results in improper segmentation of the sentence structure, which obscures the intended meaning.