- \(NC_3\): This compound exists as cyanogen (\(C_3N_2\)), a well-known compound.
- \(NC_5\): This compound does not exist. There is no stable compound formed between nitrogen and five carbon atoms in the form of \(NC_5\).
- \(SbCl_3\): This is a well-known compound, antimony trichloride.
- \(NI_3\): This is a known compound, nitrogen triiodide, which is highly explosive.
Thus, the correct answer is (B), as \(NC_5\) does not exist.