If a Macroeconomist Studying the Causes of Unemployment Asserts That

If a macroeconomist studying the causes of unemployment asserts that a particular change in technology will cause the rate of unemployment to decrease by ten percent,then this macroeconomist is at which step in the process of developing an economic model?

A) Identify the endogenous variables.
B) Develop a model.
C) Compare the model with the data.
D) Identify the exogenous variables.
E) Conduct prediction and policy analysis.