Answer:
Multiple stimulus.
Step-by-step explanation:
Multiple Stimulus Preference assessment without replacement is the process in which a teacher creates a hierarchy matching the child's preferences.
This type of assessment is appropriate for the children to help them select the preferred items from a large number of items.
In this method, a teacher places an edible item or a toy before the child or the client and allow him/her to select one item from the array of the items. After the selection of item, the selected item is removed after every trial.
In this method, the first few items that the child selects are considered the highly preferred item.
In the given case, Sam is using Multiple Stimulus preference assessment.