Detailed Solution:
The correct answer is “Both A and R are correct, and R is correct explanation of A”.
The Dandi March, also known as the Salt March, was led by Mahatma Gandhi in 1930.
The purpose of the Dandi March was to protest the British monopoly on salt production and sales, and to assert the right of Indians to produce and sell salt. This was part of Gandhi's effort to support and uplift the poor, who were affected by the salt tax imposed by the British.