Question

	Column I		Column II
a	Natural active	p	Immunity level oped by heredity
b	Artificial passive	q	From mother to fetus through the placenta
c	Artificial active	r	Injection of antiserum to travelers
d	Natural passive	s	Fighting infection naturally
		t	Induced by vaccination

Match the column and choose the correct combination

• A. a-s,b-t,c-q,d-r
• B. a-p,b-q,c-r,d-t
• C. a-t,b-s,c-r,d-p
• D. a-s,b-r,c-t,d-q

Answer 1

The correct option is D a-s,b-r,c-t,d-q

• Naturally acquired active immunity occurs when a person is exposed to a live pathogen and develops a primary immune response against infection, which leads to immunological memory.
  
• Artificially-acquired passive immunity is an immediate, but short-term immunization provided by the injection of antibodies, such as gamma globulin, that are not produced by the recipient's cells. These antibodies are developed in animals and then injected into another individual who has a chance to get the infection (such as travelers going to a particular infection site).
  
• Artificially acquired active immunity can be induced by a vaccine, a substance that contains antigen. A vaccine stimulates a primary response against the antigen without causing symptoms of the disease.
  
• Naturally acquired passive immunity occurs during pregnancy, in which certain antibodies are passed from the maternal blood into the fetal bloodstream in the form of IgG through the placenta.
  

So, the correct answer is 'D'.