Aresearcher is training laboratory rats to run a complex maze. each time the rats learn a new part of the maze, they are rewarded with a pellet of food. within a few hours, the rats have learned the entire maze. what did the researcher use to teach the rats the maze?

Which sentence contains an allusion? a. pamela and her twin are as alike as two peas in a pod, and they do everything together. b. pamela has a weakness for chocolates, which she says she's had since early childhood. c. pamela's face was as white as a ghost when she learned the shocking news about her brother. d. pamela's backyard looks like the garden of eden, with dozens of green and lush plants. e. pamela found herself trapped between a rock and a hard place, and she didn't know what to do.