Which one of the following activities would fall under 'industry' under the Industrial Disputes Act, 1947

(A) Welfare activities or economic adventures undertaken by government or statutory bodies

(B) A charitable institution that makes no profit but hires the services of employees as in any other business but the goods and services which are the output, are made available at a low or no cost to the indigent poor

(C) Physical Research Laboratory, Ahmedabad carrying on research not for the benefit of others and not engaged in commercial activity

(D) Posts and Telegraphs Department.