I would say c is the answer
No caffein,there is a factor that must not be changed when conducting an experiment,known as controlled variable
Answer:
Explanation:
<h2>
Homotropic effector-</h2>
<h2>Both -</h2>
The phrase 
is relevant and can be applied for homotropic effector molecules since the heterotropic effector molecules have the possibility and affinity to change the sigmoidal curve to a more potential hyperbolic curve contingent upon the allosteric effector to be positive or negative modulator.
The expression isn't relevant for both homotropic and heterotrophic effectors since the two of them can tie to the allosteric site of allosteric enzymatic compounds.
The phrase 
is significant and can be applied for both homotropic and heterotropic effectors.
The expression 
is significant and applied for homotropic effectors just as when substrate molecules tie to the allosteric site of enzyme then it is regarded as homotropic effectors. The heterotropic effectors are effectors apart from substrate molecules.
The phrase 
is not applied and insignificant to none of the heterotropic or homotropic effector molecules since 
is significant for the enzymes that obey the Michaelis-Menten equation, but allosteric enzymes do not obey the Michaelis-Menten equation. Homotropic and heterotropic effectors are viable and efficient for allosteric enzymatic chemicals that don't contain
The answer would be the hippocampus it is responsible for the formation of the nerves to make long-term memories.
