18.
The answer is: C
Explanation
The correct option is C: Addressee.
According to Section 2(1)(b) of the Information Technology Act, 2000, an addressee means a person who is intended by the originator to receive the electronic record but does not include any intermediary.
An intermediary, as defined in Section 2(1)(w) of the same Act, means any person who on behalf of another person receives, stores or transmits that record or provides any service with respect to that record.
An originator's agent, as defined in Section 2(1)(za) of the same Act, means a person who has the authority to act on behalf of the originator in respect of an electronic record.
A key holder, as defined in Section 2(1)(n) of the same Act, means any person holding a private key corresponding to the public key listed in a Digital Signature Certificate.