Gandhiji started a movement called the Civil Disobedience Movement in violation of the Salt Laws. The Salt Laws were imposed by the British colonial government in India, which made it illegal for Indians to produce or sell salt independently, forcing them to buy salt from the British. The Civil Disobedience Movement was a nonviolent protest against this unjust law, and it aimed to challenge British authority and demand independence for India. Non-Cooperation Movement (option 1) was another movement initiated by Gandhiji but it was not directly related to the violation of the Salt Laws. Swadeshi Movement (option 2) was a movement promoting the use of Indian-made goods and boycotting British goods, but it was also not directly related to the violation of the Salt Laws. Therefore, option 3 - Civil Disobedience Movement is the correct answer as it specifically addresses the movement started by Gandhiji against the Salt Laws.