June 2022
@05cadams If you're talking about the game's program files, then it's easy to move them. Open your Origin game library, right-click on the Sims 4 icon, and select Move Game, then choose the destination folder on D.
For the user data, i.e. saves, mods, etc., you can move the Documents directory to D, which is simple and supported by Windows:
https://www.tenforums.com/tutorials/74952-move-location-documents-folder-windows-10-a.html
Or you can use a symbolic link to point the game to your preferred location on D. You can move the Electronic Arts folder or the Sims 4 folder inside it; just make sure to get the file path exactly right. If you have questions about that or any other part of the process, please ask me before doing anything as it's a lot easier to do before there's anything to fix.
In either case, back up your saves and other critical Sims 4 data beforehand.
June 2022 - last edited June 2022
Thank you @puzzlezaddict! You are amazing. I have seen you all over questions on this site. I just moved my entire documents folder using the first link in your most recent reply. I had been meaning to do that regardless, I just worried it could cause some issues. I have also made links to folders and such before too, but forgot all about that feature on windows!
Thank you again for all your helps, I really appreciate it all!