Answer:
automatically
Step-by-step explanation:
You can tell power-point to start a video added to it upon clicking it or another way to do it is to specify that it should play automatically as soon as the slide appears in the course of the slide show or presentation. One can go about it in different ways; using the audio/video tools playback tab to start the video immediately the slides appear or; starting the video or audio after a delayed period using the animation options.