Final answer:
B) Integral Cryptanalysis is the correct technique described in the question, which differs from Differential Cryptanalysis and involves using sets of chosen plaintexts with varying parts. It is used to find structural properties in encryption algorithms that can be exploited. The question also references the Zimmerman Telegram, which used a Transposition Cipher.
Step-by-step explanation:
The technique described in the question is known as Integral Cryptanalysis. Unlike Differential Cryptanalysis, which studies how differences in input can affect the resultant differences at the output, Integral Cryptanalysis involves using sets or multisets of chosen plaintexts. In this method, part of the plaintext is held constant while another part is varied through all of its possible values. The aim is to uncover certain properties about the algorithm's structure, which can be exploited to break the cipher.
As a reference to ciphers, the Zimmerman Telegram is mentioned as having employed a Transposition Cipher, where blocks of plaintext are rearranged according to a rule. Commonly, it involves dividing the plaintext into equal-sized blocks and then permuting the letters within each block. A keyword might be used to decide those permutations, significantly altering the order of letters in each block.