Big Bus Transportation operates regional bus routes. In a recent budget performance report, there was an unfavorable "quantity" variance related to fuel. How many of the following would help explain the variance? The cost of fuel unexpectedly decreased. Poor weather caused the cancellation of more routes than usual. Labor union contract disputes led to increased wages for all bus drivers. More fuel-efficient engines were recently put in to service on company buses. co C2 C3 0 1