Final answer:
Lyme disease is an infection caused by the bacterium Borrelia burgdorferi, making it the correct answer among the provided options.
Step-by-step explanation:
The student is asking which of the given options is an infection. An infection is typically described as the invasion of the body by pathogenic microorganisms that cause disease. With this definition in mind:
- Osteoarthritis is a type of arthritis that occurs when flexible tissue at the ends of bones wears down.
- Polydactyly is a condition where a person has more than five fingers or toes.
- Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted to humans through the bite of infected black legged ticks.
- A sprain is an injury to a ligament caused by tearing the fibers of the ligament.
- Bursitis is the inflammation of a bursa, typically one in the knee, elbow or shoulder.
Hence, the correct answer is C. Lyme disease, as it is the only option that represents an infection.