Which of the following attacks is any form of cryptanalysis where the attacker can observe the operation of a cipher under several different keys whose values are initially unknown, but where some…

Adaptive chosen-ciphertext attacks allow the attacker to submit arbitrary ciphertexts and receive plaintexts adaptively, with no requirement for a mathematical relationship between keys.

Chosen-ciphertext attacks let the attacker select ciphertexts to decrypt to gather information, but do not involve observing a cipher under multiple mathematically related keys.

Chosen-plain-supermodel is not a recognized cryptanalytic attack; it is a fictitious distractor option.

A related-key attack specifically targets scenarios where the attacker can observe cipher operations under several keys whose values are unknown but whose relationships to each other are mathematically known. This relationship allows the attacker to deduce key material or plaintext by comparing outputs across the related keys, making it distinct from other attack models.