A Rectangular Plate in Plane Stress Is Subjected to Normal $\sigma _ { x } = 35 \mathrm { MPa } , \sigma _ { y } = 26 \mathrm { MPa }$

A rectangular plate in plane stress is subjected to normal stresses $\sigma _ { x } = 35 \mathrm { MPa } , \sigma _ { y } = 26 \mathrm { MPa }$ , and shearstress $\tau _ { x y } = 14 \mathrm { MPa } .$ The ratio of the magnitudes of the principal stresses $\left( \sigma _ { 1 } / \sigma _ { 2 } \right)$ is approximately:

A) 0.8
B) 1.5
C) 2.1
D) 2.9