Which statement best describes contraction joints and expansion joints in concrete pavements?

• A. Contraction joints prevent thermal expansion; expansion joints prevent shrinkage cracks.
• B. Contraction joints control cracking due to shrinkage; expansion joints accommodate thermal movement between slabs.
• C. Contraction joints are decorative; expansion joints are structural.
• D. Contraction joints are used only in asphalt; expansion joints are used only in concrete.

Answer: (B)