A Wire of Resistivity ρ Must Be Replaced in a Circuit

Multiple Choice

A wire of resistivity ρ must be replaced in a circuit by a wire of the same material but four times as long.If,however,the total resistance is to remain as before,the diameter of the new wire must

A) be the same as the original diameter.
B) be one-half the original diameter.
C) be one-fourth the original diameter.
D) be two times the original diameter.
E) be four times the original diameter.