California state statute requires daycare centers to perform background checks on all workers before allowing them to work with children. Lots of Fun Day Care fails to performja background check on Sarah, who has a previous conviction for injury to a child. If Sarah injures a child while working at Lots of Fun, Lots of Fun could be sued under the doctrine of:________
1. caveat emptor
2. res ipsa loquitor
3. negligence per se
4. a violation of the Good Samaritan statute.