Which of the following could be considered a leading indicator to predict changes in the real gdp?

It's actually (Economist Calculations Which Accurately Predict Business Cycles)

because of its location and commercial importance, atlanta was used as a center for military operations and as a supply route by the confederate army during the civil war. therefore, it also became a target for the union army. general william tecumseh sherman and his troops captured the city in 1864.

i am pretty sure the awsers is d.