Which WMI class can you use to determine a system's last bootup time?

Which WMI class can you use to determine a system's last bootup time?

• Win32_OperatingSystem
• Win32_BootEvent
• Win32_ComputerSystem
• Win32_BIOS             

EXPLANATION

Win32_OperatingSystem includes a property called LastBootUpTime, which is the time when the system last booted up.
Win32_ComputerSystem and Win32_BIOS do not have any properties that can be used for this.
Win32_BootEvent does not exist.