The two steps would be B. Select the "Choose only one value" checkbox on the pick list field. and D. Change the field type from a multi-select picklist field to a picklist field.
What does the admin need to ensure?
The administrator needs to ensure that users can only select one value for the Shoe Style field. This can be achieved by modifying the field type and enabling the "Choose only one value" checkbox.
Option A is not necessary as the administrator is not changing the values of the Shoe Style field. Option C is not necessary as the administrator is not deleting any existing data.