Which is true statement about KMnO₄?

${\mathrm{MnO}}_4^{\mathrm{\Theta }}\text{ changes to }{\mathrm{Mn}}^{2+}\text{ in basic solution. }$

Its solution is unstable in acidic medium.

$\text{ It is self indicator in }{\mathrm{Fe}}^{2+}\text{ or }{\mathrm{C}}_2{{\mathrm{O}}_4}^{2-}\text{ titration. }$

It has purple colour.