Answer:
testing effect
Explanation:
Testing effect: The term testing effect refers to the process of a person's memory and learning being facilitated or stimulated through the incorporation of the rehearsal or practice test in the person's learning regime. It talks about the process of retrieval that has a great implication on the memory or learning of a person.
Testing effect has a great impact on the end result of an individual's test being taken many times.
Example: A multiple attempts to any competitive exam leads a person to get better results than before as it can increase the score.
In the question above, the change in performance may best account for the testing effect.
Middle class youth do not become the same as lower class youth because there in different situations and different home environments!
Answer: Positive externality
Explanation: Positive externality is the concept in which the service produced and the consumption of that service will provide benefit a third party who is not a part of the process.
While producing fertilizer , it is providing a unintentional benefit to the community surrounding(third party) by keeping the insects away through exerting gases so that they don't cause insect bites or other problem.
Other options are incorrect because negative externalities are negative consequences face by the third party in a process. Comparative externality is related with comparison and pecuniary externality is increment or decrement in market price of service by action of economic actor .
