Step 1: Understand the question.
We need the CrPC, 1973, section that says a person arrested without a warrant must be produced before a Magistrate within 24 hours.
Step 2: Know why this rule exists.
This is a safety net against being locked up unfairly. It makes sure a judge quickly checks whether the arrest and detention are justified. It also supports the right under Article 22(2) of the Constitution.
Step 3: Find the right section.
Section 57 of the CrPC says the police cannot keep an arrested person for longer than is reasonable, and in any case not more than 24 hours (not counting travel time) without a special order of a Magistrate under Section 167.
Step 4: Check the other sections.
Section 164 deals with recording confessions and statements. Section 51 deals with searching an arrested person. Section 41 deals with when police may arrest without a warrant. None of these fixes the 24-hour production rule.
Step 5: Confirm the match.
Only Section 57 sets the 24-hour limit for producing the arrested person before a Magistrate.
Step 6: State the answer.
The correct provision is Section 57.
\[ \boxed{\text{Section 57}} \]