Answer:
The appropriate types of validity or this test would be statistical and internal validity.
Explanation:
To understand the answer we need to evaluate the following:
External validity: Is the kind of validity we could find outside the context of the study. In this type of case, we could look expect the same results in different experiments. In our case, we can't because we can't change kittens fo puppies, in that case, our study won't be valid.
Construct Validity is the way we have to verify the inferences made by the theory. In our case, we don't have a theory that suggests that cat videos can reduce stress. So we couldn't check if the theory is correct.
Statistical validity is the type of validity that translates behavior into data leading us to know the reaction to a certain stimulus by our population.
Internal validity is the type of validity that shows if a certain cause can generate an effect. In our case the effect of cat videos on population and the effect of the interactions on stress.