One is rows the other is columns
because it has ns1 electron configuration like the alkali metals
The answer is D. Okay l hope this helps
Answer : The change in boiling point is, 
Explanation :
Formula used :

where,
= change in boiling point = ?
i = Van't Hoff factor = 3 (for MgI₂ electrolyte)
= boiling point constant for water = 
m = molality = 0.615 m
Now put all the given values in this formula, we get


Therefore, the change in boiling point is, 