This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology (General Propeies, DNA Viruses), Subject name: Microbiology
All are true about Parvovirus B-19 except - 
Select and explain. 
A. <10% spread by transplacental route, B. Parvovirus B19 exclusively infects man, C. It is a DNA virus, D. Affects erythroid progenitors but individuals who totally lack Blood Group P Antigen are resistant to Infection
A: <10% spread by transplacental route
Answer: A: <10% spread by transplacental route 
Explanation: <10% spread by transplacental route is not true about Parvoviruses. Parvoviruses: Parvoviruses are the smallest of the DNA viruses belonging to the family Parvoviridae. They are icosahedral, nonenveloped viruses containing a single-stranded DNA. Human parvovirus B19 (B19) is the only known parvovirus that is pathogenic for humans, and it shows tropism for erythroid progenitor cells. Tropism for RBCs: It infects RBC precursors by using P blood group Ag as receptor. Transmission: Parvovirus B19 exclusively infects humans, most commonly by the respiratory route, followed by blood transfusion and transplacental transmission (occurs in 30% of cases with maximum risk in the second trimester).