The density d of an object is found by dividing the mass m of the object by its ...

Choice A is correct. The density d of an object can be found by dividing the mass m of the object by its volume V. Symbolically this is expressed by the equation d = \(\frac{m}{V}\). Solving this equation for m yields m = dV. 

Choices B, C, and D are incorrect and are likely the result of errors made when translating the definition of density into an algebraic equation and errors made when solving this equation for m. If the equations given in choices B, C, and D are each solved for density d, none of the resulting equations are equivalent to d = \(\frac{m}{V}\).