In humans, ringworm disease is caused by
Bacteria
Fungi
Nematodes
Viruses
As discussed in Fungal Diseases -
Ringworm or Tinea
Pathogen: Fungi belonging to genera Trichophyton, Epidermophyton & Microsporum
Mode of infection: from soil or towel, clothes, combs of infected persons
Effects:
Symptoms:
Hence, the correct option is (b).