Why can’t all mixtures be classified as solutions
a.) not all mixtures are homogeneous
b.) not all mixtures are heterogeneous
c.) mixtures are made of only one substance
d.) not all mixtures have solutes and solvents

C

Explanation: C because a solution is a homogenous mixture at the molecular or ionic level of two or more pure substances that do not react with each other, whose components are in variable proportions. It can also be defined as a homogeneous mixture formed by a solvent and for one or several solutes.

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petroleum? coal maybe?