What was the effect of Congress organisational changes at the Nagpur session on the movement?

Correct answer: They helped spread Congress among the masses

At the Nagpur session, Congress adopted organisational changes designed to create a wider mass base, including work through provincial units and local-level committees. These reforms made participation easier for ordinary people in towns and villages and improved coordination of the Non-Cooperation Movement. Congress did not become an elite body, abolish all provincial organisation or reject non-cooperation. Hence option A is correct.