The correct IUPAC name of the following compound is:
\( 4 \) - methyl - \( 2 \) - nitro - \( 5 \) - oxohept - \( 3 \) - enal
\( 4 \) - methyl - \( 5 \) - oxo - \( 2 \) - nitrohept - \( 3 \) - enal
\( 4 \) - methyl - \( 6 \) - nitro - \( 3 \) - oxohept - \( 4 \) - enal
\( 6 \) - formyl - \( 4 \) - methyl - \( 2 \) - nitrohex - \( 3 \) - enal