The diagram shows the stress versus strain curve for materials $A$ and $B$. From the curves,we infer that:

The strain-stress curves of three wires of different materials are shown in the figure. $P, Q$ and $R$ are the elastic limits of the wires. The figure shows that

Which one of the following is the Young's modulus (in $N/m^2$) for the wire having the stress-strain curve shown in the figure?

The graph shows the behavior of a length of wire in the region for which the substance obeys Hooke's law. $P$ and $Q$ represent:

Assertion $(A)$: Ductile metals are used to prepare thin wires.
Reason $(R)$: In the stress-strain curve of ductile metals,the length between the points representing elastic limit and breaking point is very small.

The diagram shows a force-extension graph for a rubber band. Consider the following statements:
$I.$ It will be easier to compress this rubber than expand it.
$II.$ Rubber does not return to its original length after it is stretched.
$III.$ The rubber band will get heated if it is stretched and released.
Which of these can be deduced from the graph?