Correct answer: A. To connect people with the pledge of complete independence
Explanation: Direct answer: Option A, to connect people with the pledge of complete independence. The Congress declared Poorna Swaraj, or complete independence, as its goal at the Lahore session in December 1929. It then decided that 26 January 1930 would be observed as Independence Day. On that day, people were encouraged to gather, hoist the national flag, make a public pledge and affirm that India should be completely free from British rule. Therefore, Option A explains the purpose. Option B is wrong because the Simon Commission was boycotted, not welcomed, by Indian nationalists. Option C is wrong because integration of princely states was mainly a later task after independence. Option D is wrong because abolition of Sati belonged to nineteenth-century social reform and was not the purpose of this observance. Memory cue: 26 January 1930 = public pledge for Poorna Swaraj; 26 January 1950 = Constitution came into force.