Which transformation is an oxidation ?

In the reaction between chlorine and HBr, a transformation of HBr into Br_2 takes place. Can this transformation be called oxidation? Which is the oxidant that brings about this oxidation?

In the reaction between chlorine and HBr transformation of HBr into Br_2 takes place. Can this transformation be called oxidation? Which is the oxidant that brings about this oxidation?

Which of the following transformations is not correct ?

Which of the following transformations is n p type ?

How is the transformation of ethanol into ethanoic acid an oxidation reaction?