Concept:Purna Swaraj means complete independence, and it was declared by the Indian National Congress at its Lahore session.Explanation:The Lahore session of the Congress was held in December 1929.Under the presidency of Jawaharlal Nehru, the Congress passed the Purna Swaraj resolution.It was decided to observe 26 January 1930 as the first Independence Day.Answer:Purna Swaraj was declared in 1929.So, the correct option is B.