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'.

Example Input: 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.
Example Output: 2

Example Input: Question: Generates hydrogen peroxide in the phagosome:
Options: <1> Myeloperoxidase <2> Carbonic anhydrase. <3> NADPH oxidase. <4> Cytochrome C oxidase. <5> Superoxide dismutase.
Example Output: 5

Example Input: Question: The hepatitis B virus:
Options: <1> It has circular double-stranded RNA as a genetic material. <2> It has circular single-stranded RNA as a genetic material. <3> It is transmitted by air. <4> Encode a reverse transcriptase. <5> It does not have tissue tropism.
Example Output:
4