In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

Q: Question: The Grignard reagents attack the epoxides to give, after the appropriate hydrolysis:
Options: <0> Carboxylic acids. <1> Cyclic amides. <2> Open aliphatic chains. <3> Open-chain alcohols. <4> Cyclic ethers.

A: pharmacology
****
Q: Question: The analysis by potentiometric redisolution is characterized:
Options: <0> By using the square wave as an element of excitation. <1> Because the redisolution stage is carried out without agitation. <2> Because the reoxidation step is carried out by an oxidizing agent. <3> Because currents are measured in the redisolution stage. <4> Because the redisolution is carried out at constant potential.

A: chemistry
****
Q: Question: The chemosmotic theory:
Options: <0> It was proposed by Singer and Nicholson. <1> Explains the mechanism of phosphorylation at the substrate level. <2> It requires that the membranes in which it forms are closed compartments. <3> It does not explain the synthesis of ATP in photosynthesis. <4> It has nothing to do with redox reactions.

A:
biology
****