Buildings of Types IV-A, IV-B, and IV-C construction designed to be greater than six stories...

Option A is an exact requirement of the 2021 International Fire Code Section 3303.5 . For Type IV-A, IV-B, and IV-C buildings designed to exceed six stories above grade plane, standpipes must be provided in accordance with IFC Section 3313, unless otherwise approved by the fire code official.

The IFC also requires a water supply for fire department operations, but that supply must be approved by the fire code official and fire chief; the code does not specifically mandate that it be a “portable” water supply. Option B is therefore incorrect.

The remaining options alter important numerical requirements. Where noncombustible protection is required and construction exceeds six stories, at least one layer , not two, must be installed on applicable building elements more than four levels below active mass timber construction before additional floor levels are erected. Required exterior wall coverings are likewise required more than four levels below active mass timber construction, rather than two.

These safeguards reduce the amount of exposed combustible construction while ensuring that effective fire department infrastructure progresses with the building.

References/Topics: 2021 IFC Section 3303.5; Sections 3313 and related construction-stage fire protection requirements.

===============