Can Southern and Northern Blotting Detect Differences Between WT and Mutant

Can Southern and northern blotting detect differences between WT and mutant β-globin gene or between WT and mRNA or both?
A)Only differences between WT and the gene can be detected.
B)Only differences between WT and the mRNA can be detected.
C)Differences between the WT and both the gene and the mRNA can be detected.
D)Neither differences between WT and the gene nor between WT and the mRNA can be detected.