Which of the following represents a nondirectional hypothesis?

A nondirectional hypothesis indicates that there is a relationship or correlation between two variables without specifying the direction of that relationship. This means it recognizes that changes in one variable could lead to either an increase or decrease in the other variable, but it does not predict the nature of that change.

In the case of the chosen option, stating that "there is a relationship between fast-food intake and childhood obesity" illustrates that you are open to finding any kind of association—positive, negative, or otherwise—without committing to a specific outcome. This makes it a nondirectional hypothesis.

The other options imply a specific direction or causal relationship; for instance, saying that fast food intake influences or causes childhood obesity suggests a specific outcome rather than simply acknowledging a potential relationship. Such directional statements indicate that one variable is having a specific effect on another, which is characteristic of a directional hypothesis instead. Thus, the selection captures the essence of a nondirectional hypothesis effectively.