Concept:Identify the disease among the options that is caused by a bacterium.Explanation:Syphilis is caused by the bacterium Treponema pallidum.It is mainly transmitted through sexual contact.Ringworm is caused by a fungus.Poliomyelitis is caused by a virus.Malaria is caused by a protozoan.Hence, the only bacterial disease listed is syphilis.Answer:C. syphilis