Find out the odd word/letters/number/number pair from the given alternatives.

Concept: In such odd-one-out classification questions, the alternatives are grouped by the type of causative agent responsible for the disease (bacterium, virus, protozoan, or fungus). Three items sharing the same agent type form the majority; the item caused by a different type of agent is the odd one out.

Tetanus, Syphilis, and Plague are all caused by bacteria, whereas Malaria is caused by a protozoan parasite transmitted by the Anopheles mosquito, confirming Malaria as the odd one out.