A plane-strain compression (forging) of a block is shown in the figure. The strain in the $z$-direction is zero. The yield strength $(S_y)$ in uniaxial tension/compression of the material of the block is $300 \: MPa$ and it follows the Tresca (maximum shear stress) criterion. Assume that the entire block has started yielding. At a point where $\sigma_x=40 \: MPa$ (compressive and $\tau_{xy}=0$, the stress component $\sigma_y$ is
- $340 \: MPa$ (compressive)
- $340 \: MPa$ (tensile)
- $260 \: MPa$ (compressive)
- $260 \: MPa$ (tensile)