In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.

[EX Q]: Question: The classical pathway of complement is activated in response to: 
 Options:  <1> Antigen-antibody complexes. <2> Direct binding of C3b to bacterial walls. <3> Microbial glycolipids. <4> Properdin <5> The C-reactive protein.
[EX A]: 1

[EX Q]: Question: The following metals can be determined by complexometric or chelometric titration: 
 Options:  <1> All without exception. <2> All except transition metals. <3> All except lithium, sodium and potassium. <4> All except alkaline earth metals. <5> All except gold and silver.
[EX A]: 3

[EX Q]: Question: The effect of anti-D gammaglobulin given to Rh negative women who have developed an Rh positive fetus is: 
 Options:  <1> Eliminate fetal red blood cells from maternal blood. <2> Destroy the antigens formed by the mother's immune system. <3> Avoid the formation of anti-Rh negative antibodies. <4> Induce the formation of maternal antibodies against fetal antigen. <5> Provide the woman with permanent active immunity.
[EX A]:
1