A String Is Composed of Two Parts, Each Made of the Same

Multiple Choice

A string is composed of two parts, each made of the same material and one having four times the diameter of the other. The string, subject to a tension T, is plucked so that a pulse moves along it at speed v₁ in the thick part and at speed v₂ in the thin part. The ratio of v₁/v₂ is

A) 1/4.
B) 1/2.
C) 1.
D) 2.
E) 4.