How to select a schematic of the coordinate vs energy representing a rearrangement reaction?
The answer is (b).  The initial step of the reaction should take energy.  Otherwise the reactant molecule itself is unstable.  The very initial portion of the curve in (c) is downward-sloped, which doesn't make sense.  If the reacting alkene could relax to a different conformation without any activation barrier, then it would do so.  But the fact that the reactant is a stable, isolable molecule with a well-defined chemical structure indicates that no such barrier-less relaxation is possible.  

Thus, (b) is a better answer than (c).