Final answer:
The question is related to experimental design in social studies research. The answer highlights the importance of strong experimental control in experiments for providing reliable results and allowing causal inference.
Step-by-step explanation:
Designs showing strong experimental control have a high level of reproducibility and can provide reliable results, allowing researchers to make causal statements about the effects of the independent variable. Key aspects of experimental design include random assignment to treatment or control groups, blinding, and statistical analysis to ensure any observed differences are due to the experimental manipulation.
When a control group is properly established, any significant outcomes observed can be confidently attributed to the intervention being tested, rather than other lurking variables. Thus, the correct answer to the student's question is:
d. Experimental controls allow comparison between groups that are different in only one independent variable.
This means that by carefully controlling experiments and limiting all variables except for the one being tested, researchers can assert that differences in outcomes are due to the manipulation of the independent variable, leading to more accurate and reliable conclusions.