The correct answer is option 2: Igneous.

Primary rocks are the rocks that are formed directly from the cooling and solidification of magma or lava. These rocks are the initial formations on the Earth`s surface and have not undergone any subsequent changes due to weathering, erosion, or metamorphism.

Option 1: Sedimentary rocks are formed from the accumulation and deposition of sediment over time. They are formed by the weathering and erosion of other rocks, and are not considered primary rocks.

Option 3: Metamorphic rocks are formed from the transformation of existing rock types through heat, pressure, and chemical reactions. They are also not considered primary rocks.

Option 4: None of these is not the correct answer because there is indeed a primary rock, which is option 2: Igneous.

In conclusion, primary rocks are formed directly from magma or lava, and the primary rock among the given options is Igneous.