Which of the following substances are found in the beach sands of many parts of Kerala? 1. Ilmenite 2. Zircon 3. Silimanite 4. Tungsten Select the correct answer using the code given below: [IAS 2006] (a) 1, 2, 3 and 4 (b) 1, 2 and 3 (c) 3 and 4 only (d) 1 and 2 only