A researcher conducts an experiment to assess the effects of alcohol on people’s sense of balance. He divides his subjects into three groups: in one group the participants drink one ounce of alcohol, in another they drink two ounces of alcohol and in the third group the participants drink soda. He then watches as each participant tries to walk on a straight line from one corner of the room to the next and notes how many times they stumble outside the line.

Experimental Research ; Independent Variable - Alcohol ; Dependent Variable - Sense of balance ; Experiment group - group 1 & 2 ; Control Group - group 3

Explanation:

This is an experimental research, where multiple groups are tested for presence & absence of test variable. This research tends to draw conclusion about impact of test variable on the groups.

This research assesses the effect of alcohol on people's sense of balance.

So, the Independent variable i.e the causal variable affecting the sense of balance is : Alcohol Consumption

Dependent variable i.e the variable effected by the independent variable (alcohol) is : Sense of balance

The research is experimental as it treats the research participants in a particular way (making them consume or not consume particular amount of alcohol).

The group treated in a particular way is the Experimental group : Group 1 & group 2 here, given 1 & 2 ounce of alcohol respectively

The group not treated with the independent test variable is Control Variable : Group 3, given no alcohol here

d is the correct answer.

b is incorrect because it makes food by itself

c is incorrect because us humans don't know how to produce their own food using the sun like plants.

a is incorrect because consumers can depend on carnivores for eating food for consumers to eat the dead organism. same thing with omnivores.