[单选题]
A mass of 50 kg is s2y /tj( izi170fbns h5qrvv namq5:b )uspended from a h(2 bs1vujriq.x+) xlncqo+-steel wire of diameter 1.0 mm and length 11.2 m. How much will the wire strqxi-l(u qxr .n1 cb2o+j+h)s vetch? The Young's modulus for steel is $20 \times 10^{10} \; N/m^2$.
A. $1.5 \; cm$
B. $2.5 \; cm$
C. $3.5 \; cm$
D. $4.5 \; cm$
