A 26-year-old woman presents to the urgent care clinic for dysuria, urinary frequency, and hematuria. Temperature is 37C (98.7F), pulse is 80/min, respiratory rate is 16/min, and blood pressure is 122/78 mm Hg. Physical examination is unremarkable. Urinalysis shows >20 white blood cells (WBC)/high power field (HPF), >10 red blood cells (RBC)/HPF, nitrites are positive, and pH is normal. What does the gram stain show for the most common pathogen causing this woman's condition?

A. Aerobic, non-enteric, mobile gram-negative rod
B. Pear-shaped motile protozoa
C. Enteric, coliform, motile gram-negative rod
D. Gram-positive cocci that grow in clusters