There is some concern about nanoparticles of certain chemical elements used by the industry in the manufacture of various products. Why ? 1. They can accumulate in the environment and contaminate water and soil. 2. They can enter food chains. 3. They can release the production of free radicals.

• A. all these
• B. 1 और 3
• C. केवल 3
• D. 1 और 2