Answer:
A. Validity group
Step-by-step explanation:
An experiment is a type of scientific research in which the researcher manipulates and controls one or more independent variables and observes the variation in the dependent variables concomitantly with the manipulation of the independent variables.
An experiment is composed of variables and groups. In the variables, you can mention:
- The dependent variable is one that can be manipulated to get the result.
- The independent variable is that which has influence on another variable, determining or affecting the result observed in the second, with precision and regularity. It is usually manipulated by the researcher in his experiments in order to seek to establish their relation and influence on the result of an observed phenomenon.
In a scientific experiment, besides the variables we can notice the presence of groups (two samples) that are compared to test a hypothesis: the control group (also called test group or testimony) and the experimental group.