Based upon the activity series below, which of the following statements are correct?
K(s) → K+(aq) + e-
Al(s) → Al3+(aq) + 3 e-
Cr(s) → Cr3+(aq) + 3 e-
Ag(s) → Ag+(aq) + e-
Au(s) → Au3+(aq) + 3 e-
(i) Ag can reduce Au3+ but not Cr3+.
(ii) Cr is a better reducing agent than Al.
(iii) K+ is a better oxidizing agent than Au3+.
(iv) Ag+ is a better oxidizing agent than K+.