<prompt> Best assessment of protein quality is done through:Net protein utilizationProtein biological valueDigestibility coefficientProtein energy ratio  <response>: Ref: Park s Textbook of Preventive and Social Medicine, 22nd edition. Page 588Explanation:Protein Energy Ratio PERIt assesses the quantity of protein rather than quality.Its percentage of energy provided by protein in diet.PER Energy from ProteinTotal Energy in DietNet Protein Utilization NPUThe best measure as it uses both biological value PBV and digestibility co-efficient DC.It is measure of protein retained out of consumed.It is product of PBV and DC divided by 100.Protein requirement inversely proportional to NPU of protein.NPU of average Indian diet is assumed to be 6550-80.NPU of common food items:o Egg - 100.o Pulses - 65o Meat-80o Milk-75.NPU Digestibility coefficient x Biological value 100Digestibility Co-efficient DCIt is percentage of protein that is absorbed from consumed.DC Protein absorbedProiein Consumed x 100Biological Value BVBV of protein is percentage of protein that is utilized by body out of absorbed.BV- Protein utilizedProtein absorbed x 100Protein efficiency ratio Weight gain per unit protein consumed.Amino acid score mg of amino acid per gram of protein mg of same amino acid per g of egg protein. 