(a) Tetanus antitoxins/tetanus toxoid
(b) The preformed antibody injected act on the pathogen immediately to provide protection.
(c) Tetanus passive acquired immunity.
(a) In the patient's body, the doctor has injected antiserum containing preformed antibodies against the causative organisms or toxin produced by it,
(b) The solution injected by the doctor had antibodies hence, the injection would protect the patient against the diseases and provide him humoral immunity.
(c) The disease against which this injection was given is tetanus caused by Clostridium tetani, which usually exists in the environment as spores and may gain access to the body through wound.
The kind of immunity that the injection containing antiserum provides is passively acquired immunity as preformed antibodies are used because the fast action is required in this emergency case.