Which statement about the IUPAC naming system for aromatic compounds is true?

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In IUPAC naming of aromatic compounds, the position of each substituent on the ring is indicated by numbers. These locants show exactly where the substituents attach to the ring, which is essential because different attachment patterns correspond to different compounds (for example, ortho, meta, and para arrangements on benzene). The numbers are written before the substituent names, so a substituent at position two is written as 2- substituent name, and for multiple substituents you list their positions as 1,2- or 1,3-, and so on, followed by the base ring name. This system uniquely identifies the compound’s structure. For a single substituent on benzene, the position is implied and no number is needed. While other conventions like arranging substituents alphabetically in the final name exist, the defining rule that distinguishes isomers is the use of numbers to indicate where substituents are on the ring.