Compound $\mathrm{A}$ used as a strong oxidizing agent is amphoteric in nature. It is the part of lead storage batteries. Compound $\mathrm{A}$ is:

${\mathrm{PbO}}_2$ is amphoteric and strong oxidizing agent and also a component of lead storage batteries.

In lead storage batteries ${\mathrm{PbO}}_2$ is used. In this Oxidation state of $\mathrm{Pb}$ is $+4$ so, it is always reduced and behaves as oxidizing agent