Three steel rods (E = 200 GPa) support a 50-kN load P. Each of the rods AB and CD has a 200 mm² cross-sectional area, and rod EF has a 625 mm² cross-sectional area. Neglect the deformation of the bar bed. What is the stress in rod EF?

a) 32.0 MPa
b) 64.0 MPa
c) 128.0 MPa
d) 256.0 MPa