That is because metamorphic rock is formed by parent rocks that are either sedimentary rock or igneous rocks and we can use the former rock type to distinguish the type of metamorphic rock, marble was igneous rock exposed to high pressure or temperature.
While the other two type of rocks are formed initially by sedimentation and volcanic movements and has no parent rocks.
The correct answer is - B. deciding how many cans of vegetables to store at a warehouse.
The quaternary economic activities do not involve physical involvement into the production, trade, or storage of the products, but instead, this type of economic activity is performed strictly by using ones brain, thus making decisions and plans that are going to be performed by the workers in the primary and secondary (occasionally in the tertiary) economic layers.