Eventhandler for multiple generated buttons C#

I have generated multiple buttons when I click on btnStart and I'd like to use booleans for each button to become true when it gets clicked so I can check the clicked buttons later on but I only know how to use the same event for every button

This is what I use to create the buttons (I left some unnecessary things out)

for (int i = 0; i < 5; i++) //I use this to horizontally generate buttons
            {
                for (int j = 0; j < 4; j++) //vertically generate buttons
                {
                    Button btnNew = new Button();
                    btnNew.Name = "btnFlag" + i;
                    btnNew.Click += new EventHandler(btnNew_Click);
                    Controls.Add(btnNew);
                    aButtons.Add(btnNew); //this is a list I use to set random bgImages
                }
            }

Now when I click on btnNew it would do all the code set for the event btnNew_Click but I can't use btnFlag1_Click because it doesn't exist, does anyone know a way to create booleans for every buttons and set one to true when a specific button is being clicked

Like: when btnFlag1 gets clicked, turn boolean btn1 to true and so on ..

Thank you in advance