Why was Constantinople renamed Istanbul

Since modern day Turkey had gone from a multiethnic, cosmopolitan Empire, to a nation state of Turks this was seen as necessary to complete this process. As such Constantinople was changed to Istanbul, and Ataturks government would pressure other countries to start calling the city Istanbul

Due to the fact that Constantinople had since the Middle Ages often been referred to as just "the city", and even today some Greeks still do refer to Istanbul as "the city". However when the Turkish Republic was founded, this changed, and the city was renamed to Istanbul

Explanation:

your answer is

to dominate europe

and i know for a fact it can't be the others

b.

one company controls all the means of production of a product.

~coco