Which organism primarily transmits the bacteria causing Rocky Mountain Spotted Fever?

The option naming the American dog tick and Rocky Mountain wood tick is accurate because these ticks are the primary vectors responsible for transmitting the bacteria Rickettsia rickettsii, which causes Rocky Mountain Spotted Fever (RMSF).

The American dog tick (Dermacentor variabilis) and the Rocky Mountain wood tick (Dermacentor andersoni) are specifically known for their role in the lifecycle of Rickettsia rickettsii. When an infected tick bites a human or animal, it can transfer the bacteria, leading to the disease.

In contrast, while deer ticks, also known to transmit Lyme disease, are not associated with RMSF, and dogs, although they may carry certain ticks, are not primary vectors for this particular illness. House flies do not play any role in the transmission of RMSF at all, as they are not vectors for this type of bacteria. Thus, the identification of the American dog tick and Rocky Mountain wood tick as the primary transmitters is critical for understanding both the ecology of the disease and the importance of tick control in preventing RMSF.