What is the recommended practice for ladder setup when accessing a roof?

• A. Place on stable ground, secure it, extend at least 3 feet above the edge.
• B. Never extend above the edge; set it on the ground.
• C. Use only a single ladder and avoid three points of contact.
• D. Place on stable ground, secure it, extend at least 3 feet above the edge, and maintain three points of contact during ascent and descent.

Answer: (D)