Detailed explanation and options for the selected question.
The main objective of the Salt March (Dandi March) led by Mahatma Gandhi was to protest against the British salt tax. Option "Demand for complete independence" is related to the Quit India Movement, not the Salt March. Option "Protest against Jallianwala Bagh massacre" is not related to this march. Option "Opposition to the partition of Bengal" is also not related to the Salt March.