ANS:B - easy removal of pattern from the mold cavity.

Draft allowance given to patterns is primarily for easy removal of the pattern from the mold cavity. Draft, also known as draft angle or taper, is a slight slope or angle applied to the vertical surfaces of a pattern used in sand casting or other molding processes. This slope facilitates the removal of the pattern from the mold cavity without causing damage to the mold or the pattern itself. When a pattern is pulled straight up from a mold cavity, it can create suction forces or friction between the pattern and the mold walls, making it difficult to remove. The draft angle allows the pattern to be easily withdrawn from the mold cavity by providing clearance and reducing frictional resistance. While draft can indirectly help compensate for shrinkage during both the liquid state (solidification) and solid state of the casting process by minimizing stresses, its primary purpose is to ensure smooth pattern removal and to prevent damage to the mold and the casting. Shrinkage compensation is typically addressed through other means such as pattern allowances, which are additional dimensions added to the pattern to account for material shrinkage during solidification and cooling.