Mean Platelet Volume (MPV)in Humans Increases with Heart Attacks and Strokes

Mean platelet volume (MPV) in humans increases with heart attacks and strokes and is used to predict recurrence as well as mortality. MPV has high heritability. A recent GWA study found MPV to be associated with SNPs on chromosomes 12, 3, and 17, respectively. These three QTLs accounted for 4-5% of MPV variance. Which of the following is a reasonable explanation?

A) Other loci may also account for significant variance of MPV.
B) These SNPs must be translocated or transposed alleles.
C) Monitoring of these SNPs should identify those at highest risk.
D) The three SNPs, when sequenced, should show high conservation.
E) The three SNPs will be found in genes responsible for stroke.