For Each of the Following Events, Ceteris Paribus, State the Effect

Essay

For each of the following events, ceteris paribus, state the effect on GDP (does it increase/decrease/remain unchanged?) and why.
A.A few small boat builders decide to move from the production of simple boats for leisure use to the production of yachts for the America's Cup.
B.You are short of cash and you need more exercise so you sell your car for $1000.
C.The Australian Tax Office gets tough on illegal unrecorded activity (the underground economy )
D.A major oil spill occurs off the coastline of an area with high unemployment levels.Many of the local unemployed are employed to help with the clean-up.