Which of the Following Has Not Been Demonstrated in Research

Multiple Choice

Which of the following has not been demonstrated in research on counterfactual thinking?

A) Positive mood prompts counterfactuals about how much worse things could have been.
B) Negative mood prompts counterfactuals about how much better things could have been.
C) Counterfactual thoughts can influence how we feel about an event.
D) The things we fail to do are more likely to prompt counterfactuals than the things we do.