问题详情

Attheendof20X1,aninvestmentcentrehasnetassetsof$1mandannualoperatingprofitsof$190,000.However,thebookkeeperforgottoaccountforthefollowing:
Amachinewithanetbookvalueof$40,000wassoldatthestartoftheyearfor$50,000andreplacedwithamachinecosting$250,000.Boththepurchaseandsalearecashtransactions.Nodepreciationischargedintheyearofpurchaseordisposal.Theinvestmentcentrecalculatesreturnoninvestment(ROI)basedonclosingnetassets.
Assumingnootherchangestoprofitornetassets,whatisthereturnoninvestment(ROI)fortheyear？
A.18·8%
B.19·8%
C.15·1%
D.15·9%

请帮忙给出正确答案和分析，谢谢！