Options Grayed-Out with GIF Files in GIMP

I was trying to add a drop shadow on an image using GIMP and was surprised that some options in the menu were grayed-out when working with GIF files. First, I thought GIFs do not work on GIMP. Searching on the Internet, I found out that GIF uses indexed color and not RGB.

For those who have this kind of concern, fret no more. When working with a GIF image using GIMP, choose Image > Mode > RGB. This will enable the options.