Deeply buried rocks in the ground undergo metamorphism due to high pressure and temperature. Depending on the direction of stress or pressure the rocks have different textures and are either foliated or non-foliated. Non-foliated rocks have different compositions due to different parent metamorphic rocks. The metamorphism of Limestone results in Marble.
Therefore the correct answer to this question is Option A. Marble.
Like you correctly said, the short-period comets are thought to originate in the Kuiper Belt, which is an area outside Neptune's orbit, which is located from thirty to fifty light-year.
