The disk that BTK sent to the television station contained just one valid file. What was the name of the file?

The name of the file is Floppy.

Explanation:

Given that,

The disk that BTK sent to the television station contained just one valid file.

We need to find the name of the file

According to given data,

The disk that BTK sent to the television station contained just one valid file.

This file is called floppy.

Floppy :

The floppy disk is storage disk. It is made of thin and flexible disk of magnetic storage, It shape of square.

Floppy disk are read  and written to by floppy drive.

Hence, The name of the file is Floppy.

object 2 because all the other ones are wrong