Answer:
b. Neon
Step-by-step explanation:
Problem;
O²⁻ is isoelectronic with which noble gas;
The ion of oxygen give is one that has gained two electrons.
Atom of oxygen = 2, 6
gaining two electrons;
O²⁻ = 2, 8
Neon is also 2, 8
So O²⁻ is isoelectronic with neon