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 of malaria diagnosis - 
Select and explain. 
A. Thick smear is gold standard to identify species, B. Thin smear is better to identify species, C. All have same incubation, D. Antibody detection is used for rapid diagnosis
B: Thin smear is better to identify species
Answer: B: Thin smear is better to identify species 
Explanation: 1. Examination of peripheral blood smears (thin and thick blood films): Gold standard method: Thick smear: More sensitive (40 times), used for quantification and malaria pigment detection Thin smears: Used for speciation Feathery tail end of the smear should be examined At least 200-300 oil immersion fields should be examined before considered as negative. 2. Incubation periods- P. vivex: 14 days, P. falciparum: 12 days, P. malariae: 28 days, P. ovale: 17 days. 4. Ab detection in serum is not used for diagnosis of malaria. It is useful for - Epidemiological survey in malaria Screening of blood bank