Question

the main exports .... india are cotton products​

Answer 1

The main export of India is cotton.

Prepositions in English Grammar

• Prepositions are small words that are used to connect two or more parts of a sentence.
• A sentence would make no sense if a proper preposition is not used.
• We add these words before nouns and pronouns or to introduce an object.
• These words can also be used to show time, location, and direction.
• Some examples of prepositions are from, upon, by, of, off, under, etc.

So the correct option is of.