Which condition is caused by the bacterium that can be spread by ticks or deer flies?

The correct choice, Tularemia, is caused by the bacterium Francisella tularensis, which can indeed be transmitted by various vectors, including ticks and deer flies. Tularemia is particularly associated with activities that expose individuals to infected wildlife, but its transmission through arthropods like ticks and flies highlights its potential impact in certain environments.

The other conditions listed are associated with different pathogens or modes of transmission. Lyme disease is primarily associated with the bacterium Borrelia burgdorferi, transmitted mainly by ticks. Rocky Mountain Spotted Fever is caused by Rickettsia rickettsii and is also primarily spread through ticks. The plague, caused by Yersinia pestis, is generally transmitted through fleas that infest rodents rather than through ticks or deer flies. Understanding the specific vectors and pathogens involved in each disease helps clarify their transmission dynamics in the context of environmental and occupational health.