Is the process of forming a pliable medium with hands or tools.
a. modeling
c. casting
b. carving
d. assemblage

Let us define each terms first:

·         Modeling is a small copy of something

·         Casting is something made up from material that hardens in the mold

·         Carving is the act or skill of creating carved objects, designs or figures

·         Assemblage is a group of people or things

Therefore,

Carving is the process of forming a pliable medium with hands or tools.

Modeling is the process of forming a pliable medium with hands or tools.

Explanation:

I think because modeling is Meanwhile we take a flexible means and use our hands to make it. it is deemed an additive method. A method of managing a sculptural tool such as clay, plaster, or wax to create a form.Modeling includes the frame up and shaping of a malleable material.