Explanation:

Let’s break it down:

- The modern postal system in India actually started in 1854, under Lord Dalhousie—none of the given options mention this, so they’re all a bit off.

- Option 1 (1937): 1937 isn’t linked to the launch of the postal system. Nothing major in postal reforms or history happened then.

- Option 2 (1921): Doesn’t tie back to any postal milestone. In 1921, there were some governance reforms, but not postal.

- Option 3 (1950): India became a republic in 1950, but postal modernization had already happened.

- Option 4 (1990): Too recent—India’s postal system was long established by then.

Option 1 (1937) is often mistakenly thought to be correct, but the actual year is 1854. Given these options, there’s no accurate answer.

What this really shows: sometimes quiz options just miss the mark. For full accuracy: India’s real “modern postal system” started way earlier, in 1854. But from your list, there just isn’t a correct one.