Which of the following statements regarding nonreinforced masonry walls is MOST accurate?

Which of the following statements regarding nonreinforced masonry walls is MOST accurate?
 
  A) Multiple wythes are rarely used to provide strength and stability in a Nonreinforced masonry wall.
  B) A concrete block wythe is commonly used in conjunction with a gypsum block wythe in nonreinforced masonry walls.
  C) Horizontal bonding between wythes can be accomplished using corrosion-resistant metal ties.
  D) A cleft wall is an opening between the exterior and interior wythes to prevent water seepage through the mortar joints.