Who can not file a complaint before the appropriate consumer forum?

The correct answer is option 3- National Commission.

National Commission can not file a complaint before the appropriate consumer forum.

A complaint before the appropriate consumer forum can be made by:
(i) Any consumer;
(ii) Any registered consumers’ association;
(iii) The Central Government or any State Government;
(iv) One or more consumers, on behalf of numerous consumers having the same interest; and
(v) A legal heir or representative of a deceased consumer.