Based on what, a form of polyalphabetic substitution uses a series of interwoven Caesar ciphers for encrypting alphabetic text?
Polyalphabetic cipher:  The Vigenère cipher is probably the best-known example of a polyalphabetic cipher, though it is a simplified special case. Vigenère cipher: The Vigenère cipher is a method of encrypting alphabetic text by using a series of interwoven Caesar ciphers based on the letters of a keyword. Vigenère cipher:  It is a form of polyalphabetic substitution.
i don't know