Why is randomization central to causal inference, and what is a simple randomization method?

Why is randomization central to causal inference, and what is a simple randomization method?

• A. It guarantees external validity.
• B. It ensures blinding of participants.
• C. It minimizes confounding by equally distributing known/unknown factors; simple method: random allocation using a random number generator.
• D. It eliminates the need for control groups.

Answer: (C)