Assertion: Magnesium sulphate ingress is more dangerous than sodium and potassium sulphate. C-S-H is not stable in the presence of magnesium hydroxide. Which of the following statements is true?
1) Magnesium sulphate ingress is less dangerous than sodium and potassium sulphate.
2) C-S-H is stable in the presence of magnesium hydroxide.
3) Magnesium sulphate ingress is equally dangerous as sodium and potassium sulphate.
4) C-S-H is not affected by the presence of magnesium hydroxide.