Dr. Stevens wants to examine the relationship between body mass index (BMI) and depression. He selects as his research subjects a sample of American athletes who are currently training for the summer Olympic Games. Dr. Stevens finds no relationship between BMI and depression. Which of the following is one problem with his research design that could have kept him from finding a relationship between those variables?a. There is a third-variable problem.
b. There is a restriction-of-range problem.
c. There is a problem with outliers in his sample.
d. There is a directionality problem.

There is a restriction-of-range problem.

Explanation:

The scientific research is important to explain the particular phenomena and prove the hypothesis. The procedure, observation and result makes the complete scientific research.

The research design methodology involves all the process that are important for the successful research and diagnose the problem related with the research. According to the Dr. Steven research, there is restriction-of-range problem as the observed sample will not be available through the entire research.

Thus, the correct answer is option (b).

a problem could be dealing witj emotional stress..all of these factors contribute to emotional stress.