Correct Option: B

Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.