No, it's not. They are part of the keyboard layout just like any other character, e.g.
". There is no special functionality to selectively disable parts of a keyboard layout, you need to create your own.
You can use Ukelele to create your own keyboard layout based on the US English defaults that does not contain some or any of the mappings that include
To remove all mappings using
Option only, open Ukelele, select File » New From Current Input Source, and select View » Show Modifiers Drawer. Select the entry that is Either Down for
Option, and all others Up or Both Up. Select Keyboard » Unlink Modifier Set, and you're done. Change the keyboard ID and name in in the Keyboard menu to prevent collisions, and save it in
~/Library/Keyboard Layouts and select it in System Preferences » Language & Text » Input Source.
This is what Keyboard Viewer shows when you press
Option: It's the same as without.