Final answer:
The correct IUPAC name for NI₃ is nitrogen triiodide, as per the IUPAC nomenclature for binary non-metal compounds.
Step-by-step explanation:
The correct IUPAC name for NI₃ is nitrogen triiodide. This is a molecular compound, and according to IUPAC naming conventions for binary non-metal compounds, the name begins with the prefix indicating the number of atoms of the element that comes second in the formula (here, iodine), followed by the root name of this element (iod) and the suffix -ide. Thus 'tri-' for three iodine atoms and 'iodide' for the element iodine results in 'triiodide'. The first element, nitrogen, does not need a prefix here because there is only one atom of it in the molecule.