the ______ was used as a material for the construction of caisson in theearly stages of development of caisson.

the ______ was used as a material for the construction of caisson in t

1.	the ______ was used as a material for the construction of caisson in theearly stages of development of caisson.
A.	Steel
B.	Timber
C.	Cast iron
D.	RCC
Answer» C. Cast iron