The sentence that is punctuated correctly is, We need to add these ingredients: baking soda, brown sugar, and salt. The correct answer is option D. The punctuation mark, colon (:) is used to introduce a series of items. But, there is a rule to be considered when to use a colon. Never use a colon if a verb or a preposition follows it. In the correct sentence, the word that precedes the colon is a noun, which makes the sentence correctly punctuated.
