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'.
Q: Question: The toxicological interest of the hair is due to:
Options: <1> His analysis allows to know the toxic exposure in the past. <2> The change in their coloration can facilitate the diagnosis of poisoning. <3> It constitutes an effective protective barrier against the action of corrosives. <4> Its growth is interrupted by the chronic consumption of amphetamines. <5> Hair analysis is of no interest in Toxicology.
A:
1