Answer: Option 'd' is correct.
Explanation:
Recession is a period in which industry and trade activity gets reduced.
Five major parts get affected due to recession are as follows:
1) Real GDP
2) Income
3) Employment
4) Manufacturing
5) Retail Sales
So, According to this only "Transportation costs is something that states saw a significant decrease in as a result of the recession.
Hence, Option 'd' is correct.