Is there a way to unsubscribe from a Subject of System.Reactive

I am new to System.Reactive and trying to understand how to use this extension for some of the scenarios.

I have basically three components, one is creating the message and the others are the receiver of the message.

public class Messager : IMessager{    private readonly Subject<int> _subject = new();    private readonly List<IDisposable> _disposables = [];    public void Dispose()    {        _subject?.Dispose();        foreach (var eachDisposable in _disposables)        {            eachDisposable?.Dispose();        }    }    public void Emit(int value)    {        _subject.OnNext(value);    }    public void OnEmit(Action<int> action)    {        _disposables.Add(_subject.Subscribe(action));    }}

The IMessager inherits IDisposable and the IMessager is registered as Scoped in the Program.cs file.

ComponentOne.razor and ComponentTwo.razor are look exactly like the below code

@inject IMessager _messager;<div><span>@value</span><div><MessageCreator/></div></div>    @code {        private int value;        protected override void OnInitialized()        {            base.OnInitialized();            _messager.OnEmit(Action);        }        private void Action(int value)        {            this.value = value;            StateHasChanged();        }    }

The MessageCreator.razor looks like:

@inject IMessager _messager;<div><button @onclick="ClickMe">ClickMe</button></div>@code {    private int count = 0;    private void ClickMe()    {        count++;        _messager.Emit(count);    }}

And they are called in the home.razor

@page "/"<div><div><ComponentOne/></div><div><ComponentTwo/></div></div>

If I click the button ClickMe on ComponentOne -> MessageCreator -> ClickMe - this increments the counter to 1. Both the components are updated with the value 1 because both are "subscribing" through OnEmit. Same goes for the ComponentTwo only with a separate instance of MessageCreator.razor.

So here's some of my questions:

Question 1: The IMessager registered with Scoped but when I tried with Transient it does not work, why? (Because ComponentOne.razor and MessageCreator.razor must get the same obejct.. I guess)

Question 2. Is there a way to unsubscribe. Let just say for certain cases the ComponentOne does not want to receive any notification?

Question 3. What I want is that a message generated from clicking on ComponentOne -> MessageCreator -> ClickMe should only receive by ComponentOne but not by ComponentTwo.(or do I have to use something other than Subjct)