The correct option is D heated
∙ Pasteurisation is a technique used to preserve milk. In this technique, milk is first boiled at 70 ℃ for 15–30 seconds and is then suddenly chilled.
∙ Boiling helps to kill the microbes already present in the milk, and chilling prevents the further growth of microbes in the milk.
∙ Hence, milk is preserved and can be stored for a relatively longer period of time. This technique was discovered by Louis Pasteur.