If You Graft Together a Long-Day Rootstock Plant and a Short-Day

If you graft together a long-day rootstock plant and a short-day scion plant,what will induce flowering?

A) Long days,since the rootstock senses day length
B) Both long and short days due to the grafting
C) Short days,since the scion produces the leaves
D) Days and nights of exactly 12 hours each
E) Nothing;the plant will be unable to correctly sense day length.