B. Proteins are said to be body building foods as they build the muscle mass of the body.

C. None of these foods are harmful to our body if taken in right quantities.

D. Vitamins and minerals which are considered as micro nutrients which are required in very little quantities can be considered as protective foods. They allow the food we eat to be properly absorbed by our body and also provides immunity against diseases.

So, the correct answer is 'Protective foods'.