Correct Answer: LN

Solution : Let's check the options –
First option: QJ; Q and J are opposite letters in the English alphabetical series.
Second option: SH; S and H are opposite letters in the English alphabetical series.
Third option: LN; L and N are not opposite letters in the English alphabetical series.
Fourth option: UF; U and F are opposite letters in the English alphabetical series.

Hence, the third option is correct.