Failing to Find a Significant Difference Between the Experimental and Control

Multiple Choice

Failing to find a significant difference between the experimental and control groups on variables that were identified as extraneous or alternative in nature suggests:

A) these variables are responsible for any observed group differences.
B) these variables are not responsible for any observed group differences.
C) the independent variable is responsible for any observed group differences.
D) the independent variable is not responsible for any observed group differences.