Question

When using the PowerPoint Online application, to add or delete a slide in a presentation, go to the __________ tab.

design
file
home
insert

Answer 1

you will have to go to the home tab 

Answer 2

on online powerpoint presentation (google)

you can:

press a + button that is located below the file button
press slide, and scroll down to new slide,
or press ctrl + to access another slide

so essentially, out of all the answers, i think home is the safest

hope this helps