Young's modulus of brass and steel are `10 xx 10^(10) N//m^(2)` and `2 xx 10^(11) N//m^(2)`, respectively. A brass wire and a steel wire of the same length are extended by `1 mm` under the same force. The radii of the brass and steel wires are `R_(B)` and `R_(S)` respectively. Then

Options

A. `R_(S)=sqrt2R_(B)`
B. `R_(S)=R_(B)//sqrt(2)`
C. `R_(S)=4R_(B)`
D. `R_(S)=R_(B)`//4`