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: It is well associated with its function:
Options: <1> Ribosomal RNA - messenger preRNA processing. <2> Messenger RNA - amino acid binding. <3> MicroRNA - inhibition of the translation of messenger RNA. <4> Transfer RNA - structural component of the ribosome. <5> Small interference RNA - processing of ribosomal RNA.
[EX A]: 3

[EX Q]: Question: The CD40 ligand molecule (CD40L or CD154) is expressed in:
Options: <1> Virgin T lymphocytes. <2> Activated T lymphocytes <3> NK lymphocytes. <4> Virgin B lymphocytes. <5> B activated lymphocytes.
[EX A]: 2

[EX Q]: Question: A rat pathogen that has fleas as vectors of transmission to humans is:
Options: <1> Rickettsia rickettsii. <2> Yersinia pestis <3> Borrelia burgdorferi. <4> Ehrlichia ewingii. <5> Brucella abortus.
[EX A]:
2