Right answer is (b) Polystyrene
Easiest explanation: Polystyrene cups are used in packaging yoghurt. Other than yoghurt, it is also used in packaging ice-creams. Amongst all varieties of Polystyrene, thermoformed HIPS(High Impact Polystyrene) in the form of small cups or larger tubs, with either an aluminum foil/plastic laminate or a paper/plastic laminate heat seal lid or closure is used.