Which of the statements about glass are correct? 1. glass is a super-cooled liquid having infinite viscosity 2. violet coloured glass is obtained by adding MnO2 3. glass is a man-made silicate 4. glass is a crystalline substance select the correct answer using the code given below:

Which of the statements about glass are correct? 1. glass is a super-c

1.	Which of the statements about glass are correct? 1. glass is a super-cooled liquid having infinite viscosity 2. violet coloured glass is obtained by adding MnO2 3. glass is a man-made silicate 4. glass is a crystalline substance select the correct answer using the code given below:
A.	1,2 and 3
B.	1,2 and 4
C.	2, 3 and 4
D.	1 and 3 only
Answer» B. 1,2 and 4