Final answer:
Oranges will have positive effects on the strength and flexibility of your voice, while apples, cheese, and chocolate do not.
Step-by-step explanation:
The food that will have positive effects on the strength and flexibility of your voice is oranges. Oranges are a great source of vitamin C, which helps to support the health of your vocal cords and prevent dryness. Additionally, oranges are hydrating, which is important for maintaining vocal flexibility.
Apples, cheese, and chocolate do not have the same benefits for the voice. While apples are generally healthy, they do not have any special properties that specifically enhance the strength or flexibility of the voice. Cheese and chocolate are more likely to cause mucus production and can potentially have a negative effect on your vocal capabilities.