If We Seek to Explain the Number of Seats Sold

Multiple Choice

If we seek to explain the number of seats sold on a particular air route,say Toronto to Halifax,over a one- year period,we would consider many variables.Which of the following variables would be endogenous to our theory?

A) the number of airline seats sold on this route
B) the price of jet fuel
C) the average salary of Canadian airline pilots
D) the number of fog days in Halifax
E) the unemployment rate in Toronto