XYZ Ltd signs a contract on 30 June 2015, agreeing to build a bridge for ABC Limited at a contract price of $40 million. XYZ Ltd estimates that construction costs will be as follows:

As more people migrated west during the gold rush, what do you think happened to the demand curve in most western markets, holding all else constant? a. there was no shift, nor any increase or decrease in quantity demanded. b. there was no shift, but there was a decrease in quantity demanded. c. the demand curve shifted to the left. d. the demand curve shifted to the right. e. there was no shift, but there was an increase in quantity demanded.