The correct answer to this open question is the following.
The question does not provide options. So what we can say is the following.
The type of evidence that this identification of a cause of behavior exemplifies is a covariation of cause and effect.
In simple terms, we can explain this concept as a process in research that confirms that for every cause there is an effect on the variables studied. This allows the researcher to measure the results of the study.
In this case, the instructor finds that people who perform cognitive exercises daily display more knowledge of problem-solving than those who do not perform cognitive exercises daily.
The other two pieces of evidence that help us identify the cause of behavior are alternative explanations and temporal precedence.
The influence of classical conditioning can be seen in responses such as phobias, disgust, nausea, anger, and sexual arousal. A familiar example is conditioned nausea, in which the sight or smell of a particular food causes nausea because it caused stomach upset in the past.
Since this is more of a simplification,i'll do the break down
18x-6x+2x
18x-8x
10x