The Authors of Your Text State That the Basic Dilemma

The authors of your text state that the basic dilemma of the social psychologist is the trade-off between internal and external validity. What is the best way to resolve this dilemma?

A) Focus on internal validity, because it is the most important for establishing causal relationships
B) Focus on external validity, because this demonstrates how research generalizes to other people and situations
C) Use both observational and correlational approaches to research
D) Replicate results using both laboratory and field studies to maximize both types of validity