If your choices are the following (see attachment), then the answer is E gene.
It is stated that hypostatic gene<span> is one whose phenotype is altered by the expression of an allele at a separate locus, in an epistasis event. So the allele altering the espistatis event is the E gene.</span>
If I am not wrong, I believe the answer is Producers. The reason as to why I say that producers is the answer is because in every food chain, there needs to be a base. That base is what provides the starting energy that will later on move up in the food chain.
Answer: b. reaction 3
Explanation: When an enzyme is present in a reaction acts as a catalyst, increasing velocity of reaction and decreasing the activation energy, when not present an enzyme the reaction velocity is very low and implies high activation energy, being unfavorable to the system