How far should the front edge of cabinets be set back from the finished surface in noncombustible walls?

The front edge of cabinets should be set back ¼ inch from the finished surface in noncombustible walls to ensure compliance with safety standards and code requirements. This setback is important to prevent any potential fire hazards that could arise from combustible materials coming into contact with heat sources or flames. Proper spacing allows for adequate air circulation and reduces the risk of ignition, contributing to a safer installation. Additionally, this clearance can aid in easier installation and maintenance of the cabinets.

The other options suggest larger setbacks, which may not be necessary or could complicate the installation process without providing additional safety benefits. The ¼ inch clearance effectively balances safety and practicality.