Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Suman Kumar
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.toppr.com/ask/question/in-the-crystal-field-of-the-complex-feclcn4o24-the-electronic-configuration-of-metal-is-found/&ved=2ahUKEwju49qGzavqAhXE73MBHbK-CvMQFjAAegQIAxAB&usg=AOvVaw3jTHTUkHhHiOPpglpQYoMY&cshid=1593591052835
sir but O2- has unpaired electrons soo I guess option A is also crt