A Composite Beam of Aluminum $\left(E_{a}=72 \mathrm{GPa}\right)$ And Steel $\left(E_{s}=190 \mathrm{GPa}\right)$ Has a Width B = 25 Mm and Heights

A composite beam of aluminum $\left(E_{a}=72 \mathrm{GPa}\right)$ and steel $\left(E_{s}=190 \mathrm{GPa}\right)$ has a width b = 25 mm and heights $h_{a}=42 \mathrm{~mm}$ and $h_{s}=68 \mathrm{~mm}$ , respectively. A bending moment is applied about the z axis resulting in a maximum stress in the aluminum of 55 MPa. The maximum
Stress in the steel is approximately:

A) 86 MPa
B) 90 MPa
C) 94 MPa
D) 98 MPa