Answer: Option (A) is the correct answer.
Step-by-step explanation:
The energy released when an electron is added to a neutral atom to form a negative ion is known as electron affinity.
So, more readily a neutral atom will gain an electron more will be its electron affinity.
For example, chlorine has 7 valence electrons, nitrogen has 5 valence electrons and oxygen atom has 6 valence electrons. So, out of these atoms chlorine will most readily gain an electron in order to become stable.
Hence, we can conclude that out of the given options chlorine (Cl) will have the highest electron affinity.