Answer:
all of the above
Step-by-step explanation:
The answer to this is all of the above. In the Microsoft Powerpoint software, you are able to add a design template as soon as you first open the software and begin creating your presentation. Aside from this, you can also add the design template you want to use when a new slide is added or all the slides have already been created. This is done by clicking on the Design tab in the top ribbon and choosing the desired template. From this tab, you are also able to select specific slides to which you want the design to be applied to.