Answer:
d) Teach her mother that colds are caused by viruses.
this question is incomplete but I have added The Answer options to your question
a) He does not have a hypothesis.
b) He only has one group. He has not established a comparison
c) He has not measured an outcome.
d) The groups were not equal to begin with.
Answer:
b) He only has one group. He has not established a comparison
Explanation:
A randomized controlled experiment can be defined as an experiment that has two groups which it randomly assigns participants to.
These two groups are:
1.) the experimental group and
2.) The controlled group on whom the study is being performed.
Now Alberti does not have any of these groups we have listed. He performed the testing on the same people before they consumed alcohol and after they consumed alcohol. Therefore this study was not comparative in nature.
