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'.

Input: Consider Input: Question: In the determination of water hardness due to the presence of Ca2 + and Mg2 + ions, the titrant reagent is used: 
 Options:  <1> Methyl orange. <2> A standard solution of potassium chloride. <3> Black Eriochrome T. <4> A standard solution of ethylenediaminetetraacetic acid (EDTA). <5> A solution of AEDT previously standardized against a solution of potassium phthalate.

Output: 4


Input: Consider Input: Question: If a sample of size 100 has a standard deviation of 10, its typical error is: 
 Options:  <1> 10 <2> 100 <3> 0.1 <4> one. <5> There is not enough data to calculate it.

Output: 4


Input: Consider Input: Question: Which of the following situations would noticeably decrease the transcription of a gene? 
 Options:  <1> The presence of a repressor and an inducing molecule. <2> The binding of RNA polymerase to DNA. <3> The presence of a repressor and a correpressor molecule. <4> The presence of an activator and its signal molecule. <5> The presence of a mutated repressor that could not bind to DNA.


Output: 3