JEE Advanced 2013 Physics question

One end of a horizontal thick copper wire of length 2L and radius 2R is welded to an end of another horizontal thin copper wire of length L and radius R. When the arrangement is stretched by applying forces at two ends, the ratio of the elongation in the thin wire to that in the thick wire is

• (A)0.25
• (B)0.50
• (C)2.00Correct
• (D)4.00