Which one of the following statements is correct?

1. (a)The National Song Vande Mataram was composed by Bankimchandra Chatterji originally in Bengali
2. (b)The National Calendar of India based on Saka era has its 1st Chaitra on 22nd March normally and 21st March in a leap year
3. (c)The design of the National Flag of India was adopted by the Constituent Assembly on 22nd July 1947
4. (d)The song ‘Jana-gana-mana’, composed originally in Bengali by Rabindranath Tagore was adopted in its Hindi version by the Constituent Assembly on 24th January 1950 as the National Anthem of India