You can choose. Use When several rules qualify on the Gift rules list.
- Give every qualifying gift: every qualifying gift is added.
- Give only one gift: with automatic adding, the gift at the top of the list is given. With a checkbox or dialog, customers pick one of the qualifying gifts, and the highest one is preselected. The cart checkboxes also become a pick-one list (with a "No gift" option) when there are two or more choices. Choose a dropdown (the default) or radio buttons under Checkbox area when choosing one in Settings > Cart offer. If any choice has a price (under Shown as free from the start), nothing is preselected until the customer picks one.
Change the order with the handle (⠿) or Move up / Move down in the … menu in the list.

Related
Create a gift rule