In geology, granite is an example of which major type of rock based on its origin?

Introduction / Context:
This question belongs to basic geology and earth science. It asks you to classify granite, a very common rock used in building and monuments, according to its origin. Understanding rock types helps explain how Earth crust is formed and how different landscapes develop over geological time.

Given Data / Assumptions:

• Granite is the rock in question.
• The options include sedimentary, igneous, metamorphic, and none of the above.
• Standard definitions of the three major rock types are assumed from school geography and geology.

Concept / Approach:
Rocks are broadly classified into three main types based on how they form. Sedimentary rocks form from the compaction and cementation of sediments like sand, silt, and clay, often in layers. Metamorphic rocks develop when existing rocks are altered by intense heat, pressure, or chemically active fluids, without fully melting. Igneous rocks form when molten material, called magma or lava, cools and solidifies. Granite is a coarse grained igneous rock that crystallises slowly deep inside Earth crust from silica rich magma. Its large mineral crystals, often of quartz, feldspar, and mica, indicate slow cooling, typical of intrusive igneous rocks.

Step-by-Step Solution:

Verification / Alternative check:
Geography and geology textbooks show granite in diagrams of intrusive igneous rocks, often alongside rocks like diorite or gabbro. They also show granite plutons and batholiths as major features in continental crust. Field examples include granite outcrops and mountain cores. These descriptions consistently label granite as an igneous rock, not as sedimentary or metamorphic, which confirms the correct classification for exam purposes.

Why Other Options Are Wrong:

Sedimentary rock formed from compacted sediments is incorrect because granite does not form from deposition and compaction of particles; it originates from cooled magma.

Metamorphic rock formed by intense heat and pressure is incorrect because, although granite may later be altered to form metamorphic rocks like gneiss, the original granite itself is not a metamorphic product.

None of the above rock types is wrong because granite clearly fits the definition of an igneous rock and is a standard example of that category.

Common Pitfalls:
Students sometimes confuse granite with gneiss, a metamorphic rock that may display banding and can form from granitic material under metamorphic conditions. Others may think all hard rocks must be igneous or metamorphic without checking formation processes. The key is to remember that granite crystallises from magma inside Earth and has large interlocking crystals, making it an intrusive igneous rock. Paying attention to both texture and origin helps avoid such confusion.

Final Answer:
Granite is an Igneous rock formed from cooled and solidified magma, making option B the correct choice.