How should eave and ridge lines be checked for straightness before beginning shingle installation?

• A. Assume straight lines and adjust later as needed.
• B. Use a tape measure to measure distances at several points along the ridge only.
• C. Begin installation with no check and rely on experience.
• D. Use a chalk line or laser line to verify straight lines across the eave and along the ridge; correct any deviations in the deck.

Answer: (D)