Which of the following methods explains the process of underwater concreting?

Which of the following methods explains the process of underwater concreting?
(i) Pumping technique
(ii) Hydro valve method
(iii) Toggle bags method
(iv) Bagged concrete method

1. Both (i) and (ii)
2. (i), (ii), (iii), and (iv)            (Ans)
3. Only (i)
4. Only (i), (ii), (iii)