Which of the following can be used as die material?
The most commonly used die materials are type IV (dental stone, high-strength) and type V (dental stone, high-strength, high-expansion) improved stones. 
Non-gypsum die materials are also available, such as acrylic, polyester, and epoxy resins. These materials are limited in their compatibility with impression materials.
Metal dies produced from electroplated impression material have moderately high strength, adequate hardness, and excellent abrasion resistance.

Phillip’s 12th edition page 211, 212
Gypsum
Epoxy resin
Electroplated silver
All of the above