What does the null hypothesis state in hypothesis testing?

In hypothesis testing, the null hypothesis serves as a foundational concept, asserting that there is no effect, no difference, or no relationship between the variables being investigated. By stating that no relationship will be found, the null hypothesis essentially acts as a baseline or starting point for statistical analysis. Researchers use it to determine whether any observed data deviations from this assumption are statistically significant enough to reject the null hypothesis in favor of an alternative hypothesis, which posits that there is indeed a relationship or effect present.

The other options highlight different aspects of hypothesis testing but do not accurately describe the null hypothesis's purpose and meaning. The expected direction of a relationship or claiming that a relationship will be found without specifying conditions does not align with the null hypothesis's fundamental role. Hence, option B accurately captures the essence of the null hypothesis in the context of hypothesis testing.