Answer:
The correct answer is - А. experiment.
Explanation:
An experiment is a type of research method used for scientific investigation to check how a natural phenomenon works and how a particular variable affected by causing or manipulating one variable.
The affected variable called the dependent variable and the variable that is changed is called the independent variable. Other than independent variables other variables should be controlled so there would be no influence on the result other than independent varibles.
The research method in which a researcher changes the value of one
variable to determine how the change affects another variable is during
Experiments.
An Experiment is usually conducted to confirm or refute claims of an
hypothesis. This is usually carried out by using two types of variables
called:
This involves changing the independent variable which causes a
corresponding change in the dependent variable
Read moire about Experiments here https://brainly.com/question/17274244
