The Calcium Carbonate from limestone was originally extracted from Seawater so the answer is choice A.
"Limestone" denotes any rock formed mostly of calcium carbonate (CaCO3), but to geologists, limestone is only one of several types of "carbonate rocks." These rocks are composed of over 50% carbonate minerals, generally the minerals calcite (pure CaCO3) or dolomite (calcium-magnesium carbonate, CaMg[CO3]2) or both.
According to SouthtownStar, for years, historian Tyrone Haymore would tell anyone who would listen about the wealth of limestone buried beneath Robbins, Illinois soil. Find out more here.