Explanation:

- National Commodity and Derivatives Exchange (NCDEX): It is an online platform for trading commodities in India, facilitating the trade of agricultural and other commodities.

- Trading Future Indexes: Future indexes allow investors to hedge risks or speculate on the future price movements of commodities without owning the physical commodity.

- Option 1: AGRODEX: A hypothetical name that might imply a broader focus on agriculture, but is not the correct name of the index.

- Option 2: AGRIDEX: This is the correct name. AGRIDEX represents the agriculture futures index started by NCDEX, providing a benchmark reflecting the price movements of select agricultural commodities.

- Option 3: FARMDEX: Another hypothetical name, suggesting a focus on agriculture or farming.

- Option 4: CROPDEX: Suggestive of a focus on crops specifically, this too is not the correct index name.