This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parasitology Pa 1 (Protozoology), Subject name: Microbiology
True about toxoplasmosis is all except - 
Select and explain. 
A. In adults toxoplasmosis is usually asymptomatic, B. IgG Abs are diagnostic in congenital toxoplasmosis, C. Definitive host is cat, D. Encephalitis is rare in immunocompetent individuals
B: IgG Abs are diagnostic in congenital toxoplasmosis
Answer: B: IgG Abs are diagnostic in congenital toxoplasmosis 
Explanation: CONGENITAL TOXOPLASMOSIS:.Diagnosis: IgM detection in fetal blood, IgA can also be used (experimental but better sensitivity) and Toxoplasma Ag in amniotic fluid, PCR to detect Toxoplasma genes. TOXOPLASMA GONDII: Three morphological forms: Sporulated oocyst, crescentic tachyzoites, tissue cyst containing bradyzoites Infective form: All three morphological forms are infectious Definitive hosts are cat and other felines Intermediate hosts are man and other mammals (goat, sheep) clinical feature:-In adults toxoplasmosis is usually asymptomatic. Encephalitis is rare in immunocompetent individuals and common in immunocompromised patients