Lucas is hosting thorben and several other dear friends at a housewarming party at his new home. during the tour of the new place, thorben plunges through a trap door partially concealed by the living room carpet and falls 20 feet into the concrete basement below. thorben breaks both legs and sues lucas. which of the following arguments will be lucas' best defense? a. thorben was not a social guest but was actually at the house for business purposes. b. the trap door was an obvious danger. c. the trap door was not there when he bought the house. d. he did not know about the trap door.