To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) USA - This option is incorrect because the correct answer is not the USA.
Option B) China - This option is incorrect because the correct answer is not China.
Option C) India - This option is correct because India has the maximum number of post offices in the world. India has a vast network of post offices, with over 155,000 post offices as of 2020.
Option D) Brazil - This option is incorrect because the correct answer is not Brazil.
The correct answer is C) India. This option is correct because India has the maximum number of post offices in the world.