Answer:
B.
Step-by-step explanation:
In the given scenario, types of cereals is independent variable and aggressive responses are dependent variable.
Independent variables can be defined as those variable is a research that can be manipulated or changed by a researcher. An independent variable illustrates the cause and reason of a result.
Whereas, dependent variable can be defined as a variable which is tested or experimented upon.
In the given case, the variable which is being tested is the number of aggressive responses, whereas the variable which is manipulated by the researcher is cereals-- the researcher used sugared cereal and cornflakes without sugar to test the result.
Therefore, the correct option is B.