This is pretty simple. Just a direct formula based question. You need to practice such questions to set your hand then only you will be able to solve the tricky ones easily.

Stress = Force / Area

= 10 / π r²

=  10

π ( 10³ )²

(  2    )

=   4 × 10

3.14×10

= 40 × 10

3.14

= 12.7 × 10 N/m²

So the stress in the wire is 12.7 × 10 N/m²