A study indicates that in general the more fruit students eat before a test, the better they do on the test. However, beyond a certain point, the more fruit students eat, the worse they do on the test. Thus, the relation between amount of fruit eaten and test performance is an example of

A curvilinear correlation.

Explanation:

A curvilinear correlation is defined to be a type of relationship between two variables, whereby in a case one of the variable is seen as it increases, so does it apply to the other variable, but this seen to happen to a certain level or time which makes one variable to do decrease while the second variable is on an increase spree. There are other cases where the two variables increase to a certain level and drops and also continue to increase with time. The scenario above is seen to outline with the explained explained variables that have been put to consideration.

think its caste system

explanation:

answer; (d) all of the above; 100%