Final answer:
Option C. The ideal limit for deflection in drywall assemblies is L/240, with a maximum not to exceed L/120. This is to prevent damage to the drywall, such as cracking, under normal service load conditions.
Step-by-step explanation:
It is desirable to limit deflection to L/240 and never exceed L/120 for drywall assemblies. When designing and constructing buildings, controlling deflection in structural members, such as floors and walls, is critical to avoid damage to materials and finishes. Deflection refers to the bending or displacement of a structural element under load. Drywall, being a brittle material, can suffer from cracking if subjected to too much deflection.
In the context of the question, L represents the span length. The ratio L/240 suggests that for every 240 units of span length, the maximum allowable deflection is 1 unit. This is a guideline for limiting deflections under normal service load conditions to ensure the drywall lining does not crack. However, it's imperative to ensure that the deflection does not exceed L/120 to maintain the integrity of the drywall assemblies.