Consider the following statements regarding the 'strength of cement':1. Strength test on cement is made on cubes of the cement-sand mix.2. Water to be used for the paste is 0.2P, where P is the water needed for normal consistency.3. The normal consistency is determined on Le Chatelier's apparatus.4. Cubes are cast in three layers in leak-proof moulds further compacted in each layer by vibration on a machine.Which of the above statements are correct?

Consider the following statements regarding the 'strength of cement':1

1.	Consider the following statements regarding the 'strength of cement':1. Strength test on cement is made on cubes of the cement-sand mix.2. Water to be used for the paste is 0.2P, where P is the water needed for normal consistency.3. The normal consistency is determined on Le Chatelier's apparatus.4. Cubes are cast in three layers in leak-proof moulds further compacted in each layer by vibration on a machine.Which of the above statements are correct?
A.	1 and 2
B.	2 and 3
C.	1 and 4
D.	3 and 4
Answer» D. 3 and 4