What key should be used at the GRUB menu to access more options?

At the GRUB menu, pressing the 'e' key is used to edit the commands before booting into a selected operating system. When you highlight a specific entry in the GRUB menu and then press 'e', it allows you to modify kernel parameters, boot options, or even change the root filesystem from which the operating system will boot. This is particularly useful for troubleshooting boot issues or to pass specific parameters to the kernel during the boot process.

The other options have different functions in the GRUB menu context. The 'Enter' key is used to boot the selected item, 'Esc' is often used to leave the GRUB menu or bring up additional options, while 'F10' typically does not have a standard function associated with the GRUB bootloader. Understanding these functionalities is key for anyone working with systems that utilize GRUB for boot management.