Name a communication device commonly used on construction sites.

The correct answer, two-way radios, are essential communication devices on construction sites due to their reliability and efficiency in facilitating instant communication among crew members over short to medium distances. Compared to other options, two-way radios are designed specifically for quick and direct communication, allowing operators to stay in constant contact, which is crucial for coordinating tasks in a dynamic and often noisy environment like a construction site.

Two-way radios typically offer better battery life and durability than smartphones, which can be susceptible to damage and may not withstand the rugged conditions commonly found on construction sites. While walkie-talkies serve a similar function as two-way radios, the former can sometimes refer to more consumer-grade devices that may not be as effective for professional use. Television sets do not serve any practical purpose for on-site communication and are not designed for real-time interaction, further distinguishing two-way radios as the most appropriate choice for this context.