<prompt> Transplacental transfer of antibodies from immunized mother to her newborn isNatural active immunityNatural passive immunityAcquired active immunityAcquired passive immunity  <response>: Ans. b Natural passive immunity. Ref. Textbook of Microbiology by Anantanarayan 6th72 Natural active immunity results from either clinical or inapparent infection by a parasite. A person who has recovered from attack of chickenpox or of measles develops natural active immunity lifelong. Artificial active immunity is by vaccines. Artificial passive immunity is immune horse serum administration Transplacental transfer of antibodies from immunized mother to her newborn is natural passive immunity. 