Following information are known abot a metal `M :`
`I.` A salt of metal M is used in the manufacture of gunpowder.
`II.` The superoxide of metal M is used as an air purifier in submarines.
`III.` The hydroxide of metal M is used for the absorption of gases like `CO_(2),SO_(2)`, etc. in eudiometry.
Identify the metal M `:`

Options

A. Sodium
B. Calcium
C. Magnesium
D. Potassium

Answer

4

Explanation

`KNO_(3)` is used in the manufacture of gupowder.
`KO_(2)` is used as an air purifier is submarines because it absorbs `CO_(2)` gas and liberates `O_(2)` gas.
`KOH` is used in eudiometry as `CO_(2) & SO_(2)` absorber.