Short Answer C
The Primary use of any word processor is to create word documents (like this editor) with the ability to format it with bold letters or underlining or italics. There are many other choices of things to do. All your choices are true but the main one is the third one down.
It can do very simple mathematical calculations if it can create tables (neither of which is possible with this editor. A is incorrect.
D is mostly incorrect. Very few word processors have built in capabilities that would help you with word games. There are some that do. Most don't.
I would hate to create fonts using a word processor. It's remotely possible, but anyone in his right mind would try using a program designed for that.. B is incorrect.