The Same DNA Probe Used to Measure MRNA Levels by Northern

The same DNA probe used to measure mRNA levels by northern blotting can also be used on a Southern blot with a restriction digest of genomic DNA.What new information can be gained from Southern blotting (that wasn't already obtained by the northern blot analysis) ?

A) the level of protein that is being translated from the mRNA transcript
B) the presence of a unique restriction fragment pattern indicating a mutation in a known restriction site
C) the size of the genomic DNA fragments,including both introns and exons
D) the size of the genomic DNA fragments and the level of protein being translated
E) the size of the genomic DNA fragments and the presence of a unique restriction fragment pattern indicating a mutation in a known restriction site