According to MO theory which of the list ranks the oxygen species in terms of increasing bond order
O₂²⁻,O₂⁺,O₂⁻,O₂²⁻
a. O₂²⁻,O₂⁻,O₂⁺,O₂
b. O+2,O₂,O²⁻,O₂²⁻
c. O₂,O₂,O₂⁺,O₂²⁻
d. O₂²⁻,O²⁻,O₂,O₂⁺