The outcome or effect variables are called:

Correct option is D

• Dependent Variables (Option D): These are the outcome variables that researchers measure in an experiment or study. The dependent variable depends on the changes made to the independent variable. For example, if you're testing the effect of studying hours (independent variable) on test scores (dependent variable), the test scores are the dependent variable because they are the outcome of changes in the independent variable. 

Information Booster:

1. Dependent Variables are critical in experimental research because they are the main variables being tested and measured.
2. In a cause-and-effect study, the dependent variable is the outcome that the researcher is interested in explaining or predicting.
3. The independent variable is the factor that is changed or manipulated to observe its effect on the dependent variable.

Additional Information:

• Triangulation Variables :Triangulation is a method used in research to confirm the validity of data by using multiple sources or methods, but it does not refer to a specific type of variable. So, it is not the correct answer.

• Extraneous Variables : These are the variables that are not the focus of the study but could affect the dependent variable. Researchers attempt to control for extraneous variables to ensure that they do not influence the outcome.

• Intervening Variables : These variables explain the relationship between independent and dependent variables. They are not the outcome variables themselves, but they may help explain why a certain outcome occurs.