When 1,3 -Butadiene Reacts with Chlorine, a 50/50

Multiple Choice

When 1,3 -butadiene reacts with chlorine, a 50/50 mixture of 3,4 -dichloro-1-butene and (E) -1,4-dichloro-2-butene is generated. When the same diene is reacted with bromine, the 3,4 -dibromo-1-butene is the predominant product.. What could explain the difference in regioselectivity?

A) The more stable intermediate bromonium ion favors 1,2 -addition.
B) The more reactive bromide anion favors the kinetic product.
C) The more reactive chloride anion favors the thermodynamic product.
D) The more stable intermediate chloronium ion favors the 1,4 -addition product.
E) The electronegative bromine destabilizes the positive charge on the β-carbon.