Data were collected in 30 urban areas on the percentage of women in the workforce. Data were collected in 2010 and again in 2014. Increases, or decreases, in this percentage were the measurement upon which the studys conclusions were to be based. What kind of design is this?

I. A two-related-samples design.

II. An observational study.

III. An experiment that uses a static group design.

A) I only

B) II only

C) III only

D) I and III only

E) I and II only