Among the following groupings which represents the collection of isoelectronic species?

Among the following group which represents the collection of isoelectronic species ?

Among the following group which represents the collection of isoelectronic species ?

Among the following groupings, which one represents the set of iso-electronic species

Among the following groupings , which one represents the set of iso-electronic species?

Which one of the following groupings represents a collection of isoelectronic species ?

Which one of the following groupings represents a collection of isoelectronic species ?

Which of the following grouping represents a collection of iso-electionic species?

Which one of the following groupinga represents a collection of isoelectronic species ? [ At.nos- Cs - 55 , Br - 35 ]