Which intrusive structure is formed within the throat of a volcano?

The formation of a volcanic neck occurs when magma solidifies within the conduit of a volcano, particularly in the throat area where the magma travels toward the surface. Over time, the surrounding softer rock may erode away, leaving behind the more resistant volcanic neck, which is composed of the solidified magma. This structure is typically characterized by a steep, often cylindrical form that represents the remnants of an ancient volcanic eruption.

The other structures mentioned do not form specifically within the throat of a volcano. A laccolith is a dome-shaped intrusive igneous rock body that forms when magma intrudes between layers of sedimentary rock, causing the overlying layers to bulge. A dike is a vertical or steeply inclined sheet of igneous rock that forms when magma intrudes into pre-existing fractures or spaces. A pluton refers to a large body of intrusive igneous rock that crystallizes from magma deep underground and does not relate specifically to volcanic thickets.

Thus, the volcanic neck uniquely fits the description of being formed within the throat of a volcano, making it the correct answer.