Concept:Net National Product at factor cost measures the total factor income earned by residents of a country after adjusting for depreciation and indirect taxes.Explanation:The formula used is:NNPfactor cost=GNP−Depreciation−Indirect taxesStart with the given GNP value:GNP=$3,050First, subtract depreciation of $700:$3,050−$700=$2,350Next, subtract indirect taxes of $120 from the result:$2,350−$120=$2,230This gives the final NNP at factor cost.Answer:The country's Net National Product at factor cost is $2,230, so the correct option is B.