Step 1: Understanding the Concept: 
Social control refers to the mechanisms by which society regulates individual and group behavior. These mechanisms are broadly categorized as formal and informal. 
- Formal Social Control: Based on explicit, written rules (laws, regulations). It is enforced by the state and specific authorities like police, courts, and government agencies. 
- Informal Social Control: Based on unwritten norms and values. It is enforced through social pressure via mechanisms like praise, shame, ridicule, and exclusion by family, peers, and the community. 
Step 2: Detailed Explanation: 
Let's analyze the options based on this distinction: 
(A) Custom: Long-established traditions and practices. They are unwritten and enforced informally. 
(B) Law: Codified rules enacted by a political authority (the state) and enforced by legal institutions. This is the quintessential example of formal social control. 
(C) Folkways: Social norms for routine or casual interaction (e.g., table manners). Violation is seen as odd but not immoral. They are informal. 
(D) Mores: Norms with great moral significance (e.g., prohibitions against theft or murder). While often codified into law, mores themselves are informal social norms enforced by social disapproval. 
Step 3: Final Answer: 
Among the given choices, only Law represents a system of formal, state-sanctioned rules, making it the correct answer.