is a type of molding in which thermoplastics are heated above melting temperature and, using an extruder, are forced into a closed die to produce a molding.

a. Injection molding
b. Blow molding
c. Thermoforming
d. Extrusion

The correct and is

D. Extrusion

Explanation:

What is extrusion?

Extrusion is a manufacturing process used to make basically pipes and hoses.

The pvc granules are melt into a liquid which is forced through a die, forming a long 'tube like' shape. The shape of the die determines the shape of the tube.

The extrusion is then cooled and forms a solid shape

Extrusion moulding is used to create products with a consistent cross-section.

are there answer choices to this question? this seems like a question where you have options to choose from.

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.