In What Type of Attack Does the Attacker Have the Ciphertext

Multiple Choice

In what type of attack does the attacker have the ciphertext of several messages that were encrypted with the same encryption algorithm,but has no access to the plaintext so he or she must try to calculate the key used to encrypt the data?

A) chosen-ciphertext
B) chosen-plaintext
C) known plaintext
D) ciphertext-only