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 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: Friedel-Crafts alkylation reactions lead to products that: 
 Options:  <1> They facilitate diazotization reactions. <2> They facilitate the reactions of formation of ethers. <3> Activate the aromatic ring against other substitutions. <4> They deactivate the aromatic ring against other substitutions. <5> None of the above.
[EX A]: 3

[EX Q]: Question: A neutral gene mutation: 
 Options:  <1> Change a coding codon by another synonym without altering the amino acid sequence of the protein. <2> A coding codon changes with a different one and the protein is functionally different. <3> It generates a non-functional protein. <4> It changes the amino acid sequence of the protein without altering its function. <5> Suppresses the effect of a previous mutation.
[EX A]:
4