1898/ several towns/ combined/ make/ Greater New York City/ became/ second/ largest/ world.

• A. 
  In 1898 several towns were combined to make Greater New York City, that became the second largest city in the world.
• B. 
  Since 1898 several towns were combined to make Greater New York City, the second largest city in the world.
• C. 
  In 1898 several towns were combined to make Greater New York City become the second largest city in the world.
• D. 
  In 1898 several towns were combined to make Greater New York City, which became the second largest city in the world.