Concept:The principle of “one man, one vote” means each member has equal voting power, regardless of shares or capital contributed.Explanation:In a co-operative society, members jointly own and control the business.Decision-making is democratic, so each member gets one vote.This rule ensures fairness and protects the interest of all members.In contrast, a public company or partnership gives voting rights based on shareholding or agreement terms.Answer:C. co-operative society