Soft and unconsolidated calcium carbonate, usually mixed with varying amounts of clay or other impurities is described as

Answer: Option B

Soft and unconsolidated calcium carbonate, usually mixed with varying amounts of clay or other impurities is described as Marl.
Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone.
Marl has been used as a soil conditioner and neutralizing agent for acid soil and in the manufacture of cement.