The figure shows the graph between stress and strain for a uniform wire at two different temperatures. Then:

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.

In plotting stress versus strain curves for two materials $P$ and $Q$,a student by mistake puts strain on the $y$-axis and stress on the $x$-axis as shown in the figure. Then the correct statement$(s)$ is(are):
$(A)$ $P$ has more tensile strength than $Q$
$(B)$ $P$ is more ductile than $Q$
$(C)$ $P$ is more brittle than $Q$
$(D)$ The Young's modulus of $P$ is more than that of $Q$

Two different types of rubber are found to have the stress-strain curves as shown. Then:

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

The stress-strain curves for brass,steel,and rubber are shown in the figure. The lines $A, B,$ and $C$ correspond to: