The Following Solvolysis Reaction Goes Through a Hydride Shift to Give

The following solvolysis reaction goes through a hydride shift to give the rearranged product.The hydrogen atom that moves is explicitly shown. When this hydrogen atom is replaced with a deuterium atom, the rate of reaction slows
Considerably.Which of the following conclusions can be drawn correctly from this result?

A) The bromide ion leaves before the hydride shift occurs.
B) The hydride shift occurs, then the bromide ion leaves.
C) The hydride shift occurs at the same time as the bromide ion leaves.
D) These data describe the presence of a kinetic isotope effect.
E) Both c and d are reasonable conclusions.