The statements that are true of heterogeneous mixtures are: they settle out and the proportions of solute to solvent may vary. The correct answer is option A. 1 and 2. Heterogeneous mixtures are considered mixtures wherein the components are not uniform and still retain their properties. Characteristics of heterogeneous mixtures are: the ratio of solute and solvent is not equal, the substances can be separated physically and they still retain their properties even if mixed with another substance.