Apple Certified Support Professional (ACSP) Practice Exam

Using Disk Utility is a crucial step when erasing the system disk for an OSX installation, as it is the built-in macOS application designed specifically for managing disks and storage devices. Disk Utility allows users to format and erase disks securely, ensuring that the chosen formatting scheme is compatible with macOS. It provides various options, such as APFS or macOS Extended formats, which are essential for a successful installation of the operating system.

When erasing a system disk, it's important to properly prepare the drive so that it can be formatted correctly and recognized by the macOS installer. Disk Utility also provides features for securely erasing disks, which can be particularly important for safeguarding sensitive information before the installation process begins.

While backing up user data is indeed important and should always be done before making significant changes to a system, it is not the step that directly relates to the action of erasing the disk. Running an antivirus scan or installing updates may be useful practices in some contexts but are not essential or relevant to the specific process of preparing a disk for a new OSX installation.