[单选题]
A mass of 50 kg is suspencdlvt. wgz *6 mft j8a+-u.k(lded from a steel wire of diametltp xeyh-t0+-zzw qg6ei ;t6+er 1.0 mm and length 11.2 m. How much will the wire stretch? The Young's modulus for steepy; e l-6i0-gtxzwq+et+zh t6l is $20 \times 10^{10} \; N/m^2$.
A. $1.5 \; cm$
B. $2.5 \; cm$
C. $3.5 \; cm$
D. $4.5 \; cm$
