The answer is C. Magnetic disk.
A card punch is a machine that punches holes in cards to represent data. Punched paper tape is a long, narrow strip of paper with holes punched in it to represent data. Magnetic disk is a storage device that uses magnetic fields to store data. Magnetic tape is a storage device that uses magnetic fields to store data on a long, narrow strip of tape.
A keyboard is an input device that allows users to enter data into a computer. The keyboard is directly connected to the computer, and the user can type letters, numbers, and symbols to enter data.
Of the options given, only magnetic disk is directly controlled from a keyboard. The user can type data into the computer using the keyboard, and the data will be stored on the magnetic disk.
Card punches, punched paper tape, and magnetic tape are all storage devices, but they are not directly controlled from a keyboard. The user cannot type data directly into these devices. Instead, the data must be entered into the computer using another input device, such as a card reader or a tape drive.
Therefore, the answer is C. Magnetic disk.