A storage area has been approved as an accessory occupancy within a retail store.

Per the International Building Code (IBC) Section 508.2, an accessory occupancy (e.g., storage within a retail store) with an area less than 10% of the main occupancy’s floor area adopts the egress requirements of the primary occupancy, here Mercantile (M). Retail stores are classified as Group M, and their storage, if accessory, doesn’t trigger separate Storage (S) egress rules unless it exceeds size or hazard thresholds. Business (B) applies to offices, not retail. Thus, egress (e.g., exits, travel distance) is governed by Mercantile requirements, making C correct.

Verified Answer from Official Source:C - Mercantile (M)

"For accessory occupancies, means of egress requirements are based on the primary occupancy type, such as Mercantile (M) for retail with accessory storage." (NCIDQ IDPX Study Guide, Section 1: Codes and Standards)

Explanation from Official Source:The NCIDQ aligns with IBC, noting that accessory areas follow the main occupancy’s egress rules to simplify design and ensure consistent safety standards.

Objectives:

Apply occupancy classifications to egress (IDPX Objective 1.2).