Final answer:
a) Yield point. The yield point corresponds to the initial departure from linearity on the engineering stress-strain curve.
Step-by-step explanation:
The point where yielding corresponds to the initial departure from linearity on the engineering stress-strain curve is the yield point.
On the stress-strain curve, the material exhibits linear behavior up to a certain point called the linearity limit. Beyond this limit, the material undergoes plastic deformation and no longer returns to its original shape and size when the stress becomes zero. The yield point is the point on the curve where plastic deformation begins.
It is important to note that the yield point is not a specific value, but rather a range of values, as the linear, elastic, and plasticity limits denote a range rather than one sharp point.