Why isn't chlorine reduced or nitrogen oxidised in the reaction between ammonium perchlorate and aluminium?
Here,

The oxidation number of chlorine in the perchlorate radical is +7 whereas, in the product side, chlorine has an oxidation number of  minus 1 in AlCl3. As the oxidation number is reduced by 8 here (gaining 8 electrons), chlorine is, indeed, reduced.

Nitrogen has an oxidation state of minus 3 in NH4ClO4 whereas, it has an oxidation state of 0 in N2 molecule in the product side. Here, the oxidation number of nitrogen has increased by 3 via losing 3 electrons. So, Nitrogen here is oxidised.


Hence, all the options are correct.