The correct answer is b) Monazite.
Monazite is a rare-earth phosphate mineral that is found in beach sands and placer deposits. It is the most important source of the rare-earth elements lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Monazite is also a source of thorium and uranium.
Bauxite is an aluminum ore that is found in lateritic soils. It is the most important source of aluminum. Bauxite is also a source of gallium, chromium, and iron.
Magnetite is an iron ore that is found in igneous and metamorphic rocks. It is the most important source of iron. Magnetite is also a source of nickel, cobalt, and titanium.
Chromite is an iron ore that is found in igneous and metamorphic rocks. It is the most important source of chromium. Chromite is also a source of iron, nickel, and cobalt.
The monazite sands of Kerala are among the richest in the world. They are found in the coastal areas of the state, particularly in the districts of Kannur, Kasaragod, and Kozhikode. The monazite sands are mined by open-cast methods and the ore is then processed to extract the rare-earth elements. The monazite sands are also a source of thorium and uranium.
The monazite sands of Kerala are a valuable resource and they are being exploited for their rare-earth elements. The monazite sands are also a source of thorium and uranium, which are used in nuclear power plants.