What is nominal cover for reinforcing steel in concrete design, and why is it important?

• A. The distance from the outer surface of the concrete to the reinforcement; it protects against corrosion and ensures durability and proper structural behavior.
• B. The thickness of the concrete around the reinforcement, regardless of corrosion considerations.
• C. The depth of the reinforcement from the bottom surface only.
• D. The minimum concrete cover required by code, independent of exposure.

Answer: (A)