Which sentence is punctuated correctly? you will need the following ingredients milk, eggs, sugar, and flour. you will need the following ingredients, milk, eggs, sugar, and flour. you will need the following ingredients - milk, eggs, sugar, and flour. you will need the following ingredients: milk, eggs, sugar, and flour.

The answer is D.  The sentence D is correctly using the colons ( : ), because one of the functions of this type of punctuation is to introduce an explanation, an example, a quotation or a series.  Other uses of the colons are between independent clauses (the second explains the first) "He didn't go to the party: he was very tired.",   and for emphasis "One thing makes her happy: swimming."

B

Explanation: