Answer:
A) The GDP increases by $300 since a dinner is considered a final service, it is part of consumption.
B) The GDP decreases by $1,200 since the laptop is imported from China, imports reduce net exports.
C) The GDP is not affected since the computer was manufactured last year.
D) The GDP increases by $500 since the cars are final products ($470 million are considered consumption and $30 million investment).