Electric Field in a Wire: a Narrow Copper Wire of Length

Electric field in a wire: A narrow copper wire of length L and radius b is attached to a wide copper wire of length L and radius 2b, forming one long wire of length 2L. This long wire is attached to a battery, and a current is flowing through it. If the electric field in the narrow wire is E, the electric field in the wide wire is

A) E.
B) 2E.
C) 4E.
D) E/2.
E) E/4.