The most important one, The one with the worse symptoms.
Not 100% sure but B sounds the most likely from what I've read...
Getting the right trainer, and keeping tight schuedle on when you need to train.
The main difference between dominant and recessive genes is that dominant genes get phenotypically exerted faster compared to genes that are being recessively transfered. These genes must have to be presented 2x more often (both alleles have to be recessive) for them to be exerted phenotypically.