Identify the correct mathematical expression for the DuPont identity.

Multiple choice question.

Return on equity $=$ Profit margin $$ Total asset turnover $$ Equity multiplier

Return on equity $=$ Operating profit margin $$ Total asset turnover $(1$ Equity multiplier$)$

Return on equity $=$ Operating margin $/$ Total equity

Return on equity $=$ Profit margin $$ Total asset turnover $(1$ Equity multiplier$)$