<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 27-year-old man visits the office with complaints of pain in his lower limb muscles and joints. He cannot remember exactly when it started, but it intensified after his recent hiking trip. He is a hiking enthusiast and mentions having gone on a recent trekking expedition in Connecticut. He does not recall any particular symptoms after the hike except for a rash on his left calf with distinct borders image provided in the exhibit. The patient does not complain of fever, chills or any changes in his vision. His vital signs show a blood pressure of 12070 mm Hg, a pulse of 97min, and respirations of 18min. There is tenderness in his left calf with a decreased range of motion in the left knee joint. No joint effusions are noted. Which of the following would be the next best step in the management of this patient?? A: Serological testing, B: Blood culture, C: Start doxycycline therapy, D: Ask him to come back after one week, E: Start erythromycin therapy,  <response>: This appears to be a patient with symptoms suggestive of Lyme disease after a recent hiking trip. The key findings are lower limb muscle and joint pain, no fever, and a characteristic rash on the calf. Lyme disease is caused by the bacteria Borrelia burgdorferi and is transmitted by tick bites. The rash described is typical of erythema migrans, which occurs in about 80 of Lyme disease cases. The next best step would be to start the patient on doxycycline therapy, which is the first line antibiotic treatment for Lyme disease. Blood cultures are rarely positive. Serologic testing can be useful but takes time to become positive after infection. Erythromycin is not the preferred antibiotic. Having the patient return in a week without treatment risks disease progression.C: Start doxycycline therapy 