Multiple choice Which of the following organisms causes jock itch of the groin? Tinea pedis Tinea unguium Tinea cruris Tinea corporis Reveal answer Fill a bubble to check yourself C Correct answer Explanation Jock itch of the groin, caused by tinea cruris, is a fungal infection that affects the skin of genitals, inner thighs and buttocks. Jock itch causes an itchy, red and often ring-shaped rash in these warm and moist areas of the body.