Which of the following is NOT a type of rock?

Correct option is B

The correct answer is (b) Trace rock.
· "Trace rock" is not a defined geological term.
· While "trace fossils" are recognized as evidence of past life preserved in rocks, "trace rock" itself doesn't refer to any specific rock type.
· Igneous rock: Forms when molten rock cools and solidifies. Examples include granite, basalt, and obsidian.
· Metamorphic rock: Forms when existing rock is subjected to intense heat and pressure, causing it to change its form and structure. Examples include marble, slate, and gneiss.
· Sedimentary rock: Forms from the accumulation and compaction of sediments, such as sand, silt, and clay. Examples include sandstone, shale, and limestone.