A Nylon Bar (E = 2 $0.05 \mathrm{~mm}$ (B) $0.07 \mathrm{~mm}$

A nylon bar (E = 2.1 GPa) with diameter 12 mm, length 4.5 m, and weight 5.6 N hangs vertically under its own weight. The elongation of
The bar at its free end is approximately: (A) $0.05 \mathrm{~mm}$
(B) $0.07 \mathrm{~mm}$
(C) $0.11 \mathrm{~mm}$
(D) $0.17 \mathrm{~mm}$