[MetsFan09]

Hi I have a question about the two questions presented below.

For the first one I was told to look for elimination favored alkyl halides but I can't find anything about the deuterium kinetic affect in my textbook or online.  What is that and how does this apply to this topic?

On the second question I was told the answer is C but why can't choice A go under rearrangement? 

[MissPhosgene]

Kinetic Isotope effect:

http://en.wikipedia.org/wiki/Kinetic_isotope_effect

There is a lot of information on it out there. A simple google search should reveal plenty of information for you to understand it.

Second question:

   They can both undergo rearrangements. I think the question is asking about relative rates (if it is, wording is poor). C will rearrange faster because there are no constraints due to the ring in A.The carbocation of C is better stabilized than the carbocation of A. Think about the conformation of 5 membered rings and the requirement for syn-planar geometry during hyperconjugative stabilization. C is not limited to those geometrical constraints. It's called stabilization, but the bond distortions are those that occur during rearrangement. When A has a carbocationic center, the ring flattens out, causing strain. The carbocation derived from C can accommodate the planar geometry of a carbocation much more efficiently.