Which NFPA standard specifies the requirements for placing and mounting portable fire extinguishers?

The correct choice, NFPA 10, specifically outlines the requirements for the selection, placement, inspection, and maintenance of portable fire extinguishers. This standard provides detailed guidance on how to properly mount and place extinguishers to ensure they are accessible and effective during a fire emergency. The focus of NFPA 10 is to ensure that extinguishers are strategically located and visible, which enhances the readiness and effectiveness of these critical fire suppression tools in various environments.

In terms of context, other NFPA standards listed do not pertain to fire extinguishers. NFPA 5 deals with fire service training and NFPA 15 outlines water spray fixed systems for fire protection. NFPA 20 focuses on the installation of fire pumps. Thus, NFPA 10 is the only standard that directly addresses the requirements related to portable fire extinguishers, making it the appropriate choice for this question.