The propositions are placed in the four corners of a square, and the relations are represented as lines drawn between them, hence the name 'The Square of Opposition. Important PointsThe proposition of square of oppositionResultant IF A is false A propositions or universal affirmatives take the form: All S are P.Example: All animals are mammals.'E' and 'I' are undetermined.If E Is false E propositions or universal negations take the form: No S are P.Example: No animals are mammals.'A' and 'O' is undeterminedIf I is falseI propositions or particular affirmatives take the form: Some S are P.Example: Some animals are mammals.'A 'is true 'E' is trueIF O is false O propositions or particular negations take the form: Some S are not P.Example: Some animals are not mammals.'E' is false 'I' is true.Hence A-IV, B ? III, C ? II, and D ? I are the correct match.