25yo female Peace Corps volunteer from Cameroon has a 4-day history of diarrhea with increasing fever. She complains of crampy lower abdominal pain and painful rectal spasms associated with bowel movements. Her bowel movements are frequent and loose, but they are of small volume. Stools contain abundant mucus; the last two stools have been bloody. On physical exam her temperature is 38.9\"0. and she has diffuse lower abdominal tenderness. The causative organism, a parasitic protozoan, can be seen in afresh stool specimen by microscopy. Its appearance is most consistent with which of the following descriptions? amorphous mononuciear ccl] With Ingested red blood cells 5 to 8 pm round. sold-fast spheres Multiple, tiny. round organisms with I'ncmbranc-bound vesicles ll'I mononuclear phagocytes Teardrop-shaped rriotilc cells With five agella