What is immigration and emigration

well for me I think

Explanation:

immigration is the movement which involves an individual moving from a present place to another environment

That is going out

WHILE

Emigration is the process where a person comes into a particular environment

That means coming in

Actually Welcome to the concept of Bond Formation.

Answer is :-

B.) O and Cl

These both are Non-Metals with high Electronegativity nature, hence none of them can share electrons to foram any bond to eventually form a Electro valentines Compound.