Question A1

In LucidChart draw a UML class diagram showing:
(a) a class Participant with a private attribute name of type String and a public operation join taking a VideoCall as argument and returning a boolean
(b) an abstract class VideoCall
(c) concrete subclasses ZoomCall and TeamsCall of VideoCall
(d) an appropriate relationship between VideoCall, ZoomCall and TeamsCall
(e) an appropriate relationship between Participant and VideoCall, demonstrating that at any one time a given participant can be in at most one video call, while a video call may have any number of participants (including zero, say, to account for scheduled calls).