What Is One Way to Combat Issues of Internal Validity

Multiple Choice

What is one way to combat issues of internal validity?

A) Do not ask people about things that occurred in the past.
B) Conduct longitudinal studies versus cross-sectional studies.
C) Never conduct a cross-sectional design.
D) Conduct longitudinal studies versus cross-sectional studies AND do not ask people about things that occurred in the past.
E) Issues of internal validity cannot be avoided.