You plan to run a hot dog stand at a forthcoming fair. You expected Rs 2000 of sales and have already spent Rs 1000 building the stand. It is nearly finished, but because the fair now clashes with a major music festival nearby you expect sales of only Rs 800. Finishing the stand will cost another Rs 300. Your rule should be to complete the stand as long as the cost of completing it is below what amount?
Correct answer B. Rs 800