What must be posted next to the communication device according to F16?

The correct choice emphasizes the importance of having clear and accessible instructions for the use of the communication device. By posting instructions next to the device, it ensures that anyone who needs to use it can do so effectively and efficiently in case of an emergency. This is crucial for maintaining safety and ensuring that appropriate actions can be taken without delay.

Having instructions readily available eliminates confusion and reduces the potential for mistakes during critical moments when quick communication is essential. It emphasizes the need for preparedness and the importance of all staff and volunteers being able to respond promptly using the tools available to them.

The other options, while they may have their own benefits, do not focus directly on the immediate use and need for clarity in operating a communication device during emergencies. An emergency contact list, volunteer sign-in sheets, or lesson schedules may be useful in other contexts, but in terms of ensuring safe and effective communication during an emergency response, clear usage instructions are paramount.