Which of the following is represented by the area enclosed by a hysteresis loop?

If the $B-H$ curves of two samples $P$ and $Q$ of iron are as shown below,then which one of the following statements is correct?

The coercivity of a small magnet where the ferromagnet gets demagnetized is $3 \times 10^3 \ Am^{-1}$. The current required to be passed in a solenoid of length $10 \ cm$ and number of turns $100$,so that the magnet gets demagnetized when inside the solenoid,is:

Draw the hysteresis curve ($B-H$ loop) and explain it.

The intensity of magnetisation $I$ is plotted against the magnetising field $H$ for different substances. The curves $A$ and $B$ shown in the adjoining figure are associated with

The figure shows the experimentally measured $B$ vs. $H$ variation in a ferromagnetic material. The retentivity,coercivity,and saturation of the material are,respectively: