Answer: may be held responsible due to careless hiring
Explanation: According to the described situation in the question , Art has the offensive background of assaulting children on the name of organizing and supervising games for them. Circus Pizza displayed the careless attitude of not investigating the background of Art before hiring.
Due to this act , Circus Pizza can be held for being showing the careless and irresponsible attitude while hiring . It can be seen as an offense too because safety of children is at risk due to Circus Pizza's behavior.