The installation of McAfee security software is optional. While installing Acrobat Reader, at step-1 there's a dialog box to select or deselect. By default, the dialog is checked, but you can proceed with or without McAfee installation.
This is not true. I experience the same thing the original poster said. I unchecked McAfee during installation and it still installed it. Now I can't uninstall it. It is grayed out in Windows -> Settings -> Apps & Features. And I keep receiving alerts on my desktop from McAfee, asking me to purchase the software. How do I shut this off!?