Answer:
Option b, Irreversible hydrocolloid impression material
Step-by-step explanation:
Irreversible is used as an impression material to take impression from edentulous jaws. It is also used in wound healing and drug delivery.
Alginate is a natural polymer found in cell wall of brown seaweed.
Its monomers are β-D-mannuronate and α-L-guluronate.
In association with Ca2+, it forms gel. It is hydrophilic in nature.