Answer:
The correct answer is option c. .odt.
Step-by-step explanation:
An .odt file extension is a type of text file, which must be opened through certain types of applications.
One of the software where you can create an .odt file is at OpenOffice.org.
Like .docx files, we can store texts, images and different styles formats.
Therefore, we can say that the correct option is option C.