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Suppose that the following Graphic User Interface (GUI) is developed by a programmer. It shows an outcome of Windows Form application with GUI controls in Visual Basic .Net. It is used to compute the required total with discount a customer. CashierApp - Visual Programming х Variable name: txtPrice Variable name: txtName Cashier App of WOU Supermarket Item Name Item Price Discount iPad Wi-Fi + Cellular 128GB - Silver 2371.00 0 Add Variable name: IstDiscount Variable name: btnAdd Variable name: IstName 21.5 inch Mac with Retina 4K display 13nch MacBook Pro - Space Gray Apple Watch Series 4 GPS 44mm Nike+ Sport Band iPhone XS Max 512GB Silver 5968.66 8990.12 1899.03 7049.51 888888 Variable name: IstPrice Variable name: btn Total Variable name: IblTotal Total 23907.32 Total Price in Ringgit (after discount) Relate the following principles of Object-Oriented Programming (OOP) based on the given GUI. Explain all the following OOP principles with any of above adopted controls. i) Class and instance ii) Encapsulation and information hiding ii) Inheritance iv) Polymorphism Support your elaborations either with related graphic/diagram illustration and/or sample of VB .Net.code.