Which of the following is not a true 3DES mode?

A.
DES-EEE1 uses 1 key

B.
DES-EEE2 uses 2 keys

C.
DES-EEE3 uses 3 keys

D.
DES-EDE2 uses 2 keys

Explanation:
The following are the correct modes for 3DES. DES-EEE3 uses three keys
for encryption. DES-EDE3 uses three different keys and encrypts, decrypts, and
encrypts data. DES-EEE2 and DES-EDE2 are the same as the previous modes, but the
first and third operations use the same key. There is no DES-EEE1 mode using 1 key.
That is a bogus answer.