Bob is interested in buying Sally’s house. During their conversation, Bob learns the following:
• The house was built in 1953.
• The roof is three years old.
• All of the appliances are in excellent shape.
• The house is heated with a natural gas furnace that was installed four years ago.
Bob is interested in buying the house, but only if the furnace is as described. What contract concept(s) should Bob’s lawyer use to protect Bob from the risk that the furnace is not as described?