Answer:
I believe that B. The colon is correctly placed and necessary because the introductory text can stand alone is the correct answer.
Step-by-step explanation:
In this sentence, the introductory text, "When Letasha went to the store, she bought several baking goods" can stand alone. But the words "milk, sugar, and cinnamon," cannot, since they don't express a complete thought.
The colon is placed after the words "several baking goods" because the food ingredients explain what these baking good are.
Therefore, B. The colon is correctly placed and necessary because the introductory text can stand alone is the correct answer.
Hope this helps! :D