Which of the following Tineas is known to affect the groin region?

Tinea cruris is specifically known to affect the groin region, which is why this is the correct answer. This fungal infection, commonly referred to as "jock itch," primarily occurs in warm, moist areas of the body. It presents as a red, itchy rash and can often be exacerbated by sweating and friction from clothing.

Other types of tinea, such as tinea capitis, primarily affect the scalp; tinea manuum targets the hands; and tinea pedis affects the feet. Each type of tinea is caused by dermatophyte fungi and is characterized by its specific location on the body, which distinguishes it from the others. Thus, tinea cruris is unique in its association with the groin area, making it the appropriate choice for this question.