Final answer:
Lyme disease, caused by the spirochete Borrelia burgdorferi and transmitted by Ixodes ticks, is the disease among the options listed that is caused by a spirochete.) Lyme disease
Step-by-step explanation:
The disease caused by a spirochete is b) Lyme disease. Lyme disease is caused by the spirochete Borrelia burgdorferi, which is transmitted by tick bites, specifically by the black-legged Ixodes ticks. These ticks act as biological vectors, transmitting the pathogen which not only causes a characteristic "bull's eye" rash but can also result in fever, fatigue, arthritis, and if untreated, more serious disorders in the nervous system, eyes, joints, and heart. Another disease caused by a spirochete is syphilis, which is caused by the genus Treponema.