Hello.
Unfortunately, there are no standard methods. The installation requirements for a particular application are set by its developers and only they (in this case, Whatsapp developers) can make changes.
The data backup and installation location of WhatsApp is determined by the system and cannot be changed manually. WhatsApp data is stored in the system's default location and cannot be changed.
However, you can try to free up C drive space, such as deleting unnecessary files or programs. Alternatively, you may consider moving other programs or files to a different drive letter to free up space on your C drive.
Hello.
Unfortunately, there are no standard methods. The installation requirements for a particular application are set by its developers and only they (in this case, Whatsapp developers) can make changes.