Reason: The mixture is said to be homogenous, if it contains single phase, On other hand, heterogenous system has, multiple phases. When, oil and vinegar are mixed together, on standing, the two liquids separates out as different phases. Hence, the mixture will be refereed as heterogeneous.
The correct answer would be homogeneous mixture. <span>There
are two types of mixture depending on the distribution of the components in the
mixture. Homogeneous mixtures are mixtures which has uniform properties
all throughout the mixture. For this case, the mixture of oil and vinegar had already achieved a uniform consistency.</span>