Dr. Schmidt-Escobar hypothesizes that drinking caffeinated soda will cause people to have higher creativity scores on a standardized creativity test than drinking decaffeinated (decaf) soda. Based on random assignment, half of her participants drink 8 ounces of caffeinated soda and the other half drink 8 ounces of decaf soda 1 hour prior to completing the creativity test. Which parametric test should she run? (The decision tree is pasted below as a guide.)