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'.

Question: The oxygen of the ethers as that of the alcohols can be protonated to generate:
Options: <1> Iminium ion. <2> Alkaloxonium ions. <3> Peroxides <4> Piranos. <5> Enaminas
2

Question: Statins are used to reduce cholesterol levels and act as analogs of the transition state of an enzyme involved in its biosynthesis. What enzyme is it?
Options: <1> 14-Alpha-demethylase. <2> Hydroxymethylglutaryl coenzyme A (HMGCoA) reductase. <3> Cyclooxygenase 2 (COX-2). <4> Squalene epoxidase. <5> Aromatase
2

Question: Fibrous cartilage is typical of:
Options: <1> Windpipe. <2> Bronchi <3> Auricular pavilion <4> Intervertebral discs. <5> External auditive conduct.
4