When Is the Content of the Kernel Ring Buffer Reset

When is the content of the kernel ring buffer reset?

A) When the ring buffer is explicitly reset using the command dmesg --clear When the ring buffer is explicitly reset using the command dmesg --clear
B) When the ring buffer is read using dmesg without any additional parameters When the ring buffer is read using dmesg without any additional parameters
C) When a configurable amount of time, 15 minutes by default, has passed
D) When the kernel loads a previously unloaded kernel module
E) When the system is shut down or rebooted