Answer:
B. Axial stress divided by axial strain
Step-by-step explanation:
Elasticity:
It is the tendency of an object to deform along the axis when an opposing force is applied without facing permanent change in shape.
Plasticity:
When an object crosses the elasticity limit, it enters plasticity where the change due to stress is permanent and the object might even break.
Yield strength:
Yield strength is the point of maximum bearable stress that indicates the limit of elasticity.
Our case:
As the stress applied is less than the yield strength, the rod is still in the elasticity state and its modulus can be calculated.
Modulus of Elasticity = Stress along axis/Ratio of change in length to original length
Axial strain is basically the ratio of change in length to original length.
So, Modulus of Elasticity = Axial Stress/ Axial Strain