Arrange the following species in order of increasing strength as oxidizing agents for species in aqueous solution:

(a) Co²⁺, Cl₂, Ce⁴⁺, In³⁺;

(b) NO₃ ^–, ClO4 ^–, HBrO, Cr₂O7 ^2–, all in acidic solution;

(c) O₂, O₃, HClO, and HBrO, all in acidic solution;

(d) O₂, O₃, ClO^–, BrO^–, all in basic solution.