Correct Answer. B. Delete unused files from the disk Freeing up disk space by deleting unused files is a direct and effective way to resolve issues related to disk space limitations when saving files.
Option A is incorrect as while saving to an external drive is a viable alternative, it does not address the issue of limited space on the primary disk.
Option C is incorrect because compressing the file might not significantly reduce its size if the disk is nearly full.
Option D is incorrect as RAM expansion does not impact the amount of disk storage available, which is what is required to save the file.