The correct answer is D, all of the above.  Toxoplasma gondii belongs to the family Sarcocystidae, suborder Eimeriina, order Eucoccidia of the phylum Apicomplexa.  It has a life cycle presenting different stages, including oocysts (the infective stage) that measure 9 to 11 µm in width by 11 to 14 µm in length containing two sporocysts and tachyzoites that are approximately 2 to 3 µm wide by 4 to 8 µm long.  Human infection may be acquired in several ways: 1) accidental ingestion of oocysts shed in cat feces; 2) ingestion of undercooked meat containing T. gondii cysts; 3) organ transplantation or blood transfusion; 4) transplacental transmission; 5) accidental inoculation of T. gondii tachyzoites.  House cats (family Felidae) are the definitive hosts for T. gondii and play an important role in the transmission of this disease.