B. Leprosy

Leprosy: 

Slowly progressive infection caused by Mycobacterium Leprae, mainly affects the skin and peripheral nerves and results in disabling deformities. M. leprae secretes no toxins; its virulence is based on properties of its cell wall. It is a bipolar disease determined by host cellular immune response. When host mounts T-cell mediated immune response it results in Tuberculoid Leprosy, and when the host is anergic and lack T-cell mediated immune response it results in Lepromatous Leprosy.