Final answer:
The mandatory requirements that necessitate changing the labeling of products are part of the D) legal requirements in the local marketplace.
Step-by-step explanation:
The mandatory requirements that necessitate changing the labeling of products, as mentioned in the question, are part of the legal requirements in the local marketplace. These legal requirements could include regulations and laws related to food labeling and consumer protection.
In the case of Flix bars in Indian markets, the use of the brown dot in a brown square symbol instead of the green dot in a green square symbol is likely required by law to indicate the presence of animal-based ingredients.