Consider the following statements about electricity and select the correct answer using the code given below: 1. Hydro-electricity is a clean source of energy. 2. Electricity is generated from water, coal, mineral oil, natural gas and atomic minerals. 3. Electricity is a relatively expensive source of energy. 4. The per head consumption of energy is an important indicator of economic development. Code:

• A.  1, 2 and 3 are correct    
• B.  1, 3 and 4 are correct
• C.  1, 2 and 4 are correct
• D.  1, 2, 3 and 4 are correct