The 4R principle is Reduce, Reuse, Recycle and Recover. This principle is environmentally friendly and would help reduce environmental pollution to an extent.
The principle directs people to
•Reduce the usage of resources. Use them only if necessary.
•Reuse the resources (or materials) if possible. For example, reusing cloth bags for shopping.
•Recycle materials if they are no longer usable.
•Recover materials; converting waste into usable resources.
Hence, the correct option is B.