Answer:
A. Put it under one government.
Step-by-step explanation:
The word "unify" means to put things together as one entity. This refers to any act of putting two or more things together into a single unit or body.
The statement "Sydney wants to unify his country" means that Sydney wants to bring the different parts of his country under one government. It means he wants his country to be ruled or governed by a single government.
Thus, the correct answer is option A.