There is some concern regarding the nanoparticles of some chemical elements that are used by the industry in the manufacture of various products. Why? They can accumulate in the environment and contaminate water and soil. They can enter the food chains. They can trigger the production of free radicals. Select the correct answer using the code given below. (a) 1 and 2 only (b) 3 only (c) 1 and 3 only (d) 1, 2 and 3