Which of the following statements regarding Zero Hour are correct ?
a. Zero Hour is an Indian innovation in the field of Parliamentary Procedure.
b. The time gap between the question hour and the agenda of house is known as Zero Hour.
c. This device has been in existence since 1962.
d. It is an informal device available to the members of the Parliament.
1. a, b 'and c
2. a, c and d
3. b and c
4. All of the above