Install VMWare Tools When the Option is Grayed Out
VMWare Workstation Player is a great tool to run Linux, Windows, Mac OSX or any operating system. VMs are great for testing operating systems or features as they can be set up fairly quickly, and they don't impede with the physical machines underlying operating system.
How to install VMWare tools if the option is grayed out
1. Shut down the VMware virtual machine.
2. Open VMWare Workstation Player and right-click on the VM. (Make sure you don’t start the VM)
3. Select the "Settings" option to edit the hardware settings.
4. Highlight the CD/Drive on the left under the Hardware tab and click on the remove button.
5. Repeat the above step to remove the Floppy Drive. (This shouldn’t be necessary, but this worked for me.)
6. Click on the "Add button" and select "CD/DVD" Drive and select finish. The right pane should have now have the "Use Physical Drive > Auto Detect" enabled. (Previously, it was the Windows ISO selected)

7. Click on "OK" to close the window, and Start the VM as normal.
8. Once it has booted to the desktop, click on the menu at the top left corner and go to "Player > Manage > Install VMWare Tools".
The option should no longer be greyed out. Click on it to install the VMWare Tools. You will also see a new tab at the bottom of the screen prompting you to install the tools.

This isn't limited to Windows 10 VMs, it should work on any VM be it Linux, macOS, or older versions of Windows.