Consider the following statements: 1. Detergents do not produce lather with hard water 2. Water gas is a mixture of carbon monoxide and hydrogen 3. Methane is the chief constituent of CNG 4. LPG contains mainly n-butane 5. The correct statements are: (a) 1, 2 and 4 only (b) 1,3 and 4 only (c) 2, 3 and 4 only (d) 1, 2 and 3 only