The correct answer is option 4: Limestone. Marble is a metamorphic rock that is formed from the recrystallization of limestone. Limestone is a sedimentary rock composed mostly of calcium carbonate. Through the process of metamorphism, which involves intense heat and pressure, the minerals in limestone undergo a chemical change and recrystallize into marble. This transformation results in the characteristic texture and appearance of marble, with its distinct patterns and colors. It is important to note that marble can come in various types and colors, depending on the impurities present in the original limestone and the conditions of metamorphism. Therefore, option 4 - Limestone, is the correct explanation for the metamorphosed form of marble.