Half the Trees in an Orchard Were Derived from Rootstock

Multiple Choice

Half the trees in an orchard were derived from rootstock "A" and half from rootstock "B," but all the trees had the same scion. If the trees grafted onto rootstock "A" were infected by a parasite that causes blossom rot, the trees grafted onto rootstock "B"

A) would be less likely to become infected because they're grafted onto different rootstocks.
B) would be more likely to become infected, since the pathogen would spread through the soil to the roots of other trees.
C) would be very likely to become infected, because the remaining scions are genetically identical to those that are already infected.
D) There's no way to determine the likelihood of infection, since genetic variability gives all the trees different characteristics.