Which of the following is a common type of commercial modular building?

Classroom modules are a common type of commercial modular building because they are specifically designed to meet the needs of educational institutions that require flexible and quick solutions for space. Modular classrooms can be constructed off-site and then transported to the final location, allowing for rapid deployment, which is essential when schools face overcrowding or need to temporarily expand to accommodate more students.

The design of modular classrooms caters to various educational needs, such as technology integration, safety standards, and accessibility. Furthermore, these structures can easily be expanded or reconfigured based on changing educational requirements, making them a practical and cost-effective solution for schools. This adaptability further emphasizes why classroom modules are classified as a common type of commercial modular building compared to the other options listed.