246. What is the best description of a stream cipher?

Вариант ответа 1 - A. The message is divided into blocks and mathematical functions are performed on each block.

Вариант ответа 2 - B. The sender must encrypt the message with his/her private key so the receiver can decrypt it with her/his public key.

Вариант ответа 3 - C. The cipher uses a key to create a keystream and XOR’s the result with the message.

Вариант ответа 4 - D. The cipher executes 16 rounds of computation on each bit?