A 2-inch diameter copper water pipe passes through a 2x4 wood stud wall. According to CPC Section 312.0, what is the minimum required diameter of the sleeve, unless the pipe is protected by other means?

• Sleeve must be at least 4 inches in diameter.
• Sleeve must be at least 3 inches in diameter.
• Sleeve must be at least 2 pipe sizes greater.
• No sleeve is required for a wood stud wall.