Examine the Following Half-Reactions and Select the Strongest Oxidizing Agent

Examine the following half-reactions and select the strongest oxidizing agent among the species listed. Cr²⁺(aq) + 2e⁻ ⇄ Cr(s) E° = -0.913 V
Fe²⁺(aq) + 2e⁻⇄ Fe(s) E° = -0.447 V
Sr²⁺(aq) + 2e⁻⇄ Sr(s) E° = -2.89 V
Co²⁺(aq) + 2e⁻⇄ Co(s) E° = -0.28 V

A) Cr ²⁺( aq)
B) Fe( s)
C) Fe ²⁺( aq)
D) Sr ²⁺( aq)
E) Co ²⁺( aq)