Which reagents from the given list are correctly matched with the corresponding step of the transformation?
a) KMnO₄, NaOH, heat, H₃O+
b) KMnO+4, NaOH, heat, H₃O+
c) NaOH, heat, H₃O+, KMnO₄
d) NaOH, KMnO₄, heat, H₃O+