Which of the following does NOT directly affect USA's GDP?

Select one:

a.Wal-Mart (a US-based retailer) buys 100 Korean-made VCRs and sells them in Roanoke, Virginia

b.stock market values in the US drop sharply

c.a construction firm sells a new house to a customer

d.a new car dealer liquidates his stocks at a loss of $100 per car

e.a Canadian tourist visits New York to see a sports game