Which disk can be inserted into the disk drive of your computer?

The correct answer is C. Floppy disk.

A floppy disk is a removable storage medium that can be inserted into a disk drive. While hard disks (D) are also used for storage, they are typically fixed inside the computer. Flat disks (A) and flip disks (B) are not recognized standard types of computer storage. Floppy disks were commonly used in the past for data storage and transfers. If you have more questions or need further assistance, feel free to ask!