Match Column-I with Column-II and select the correct  answer by the given codes. 
 

	Column -I		Column -II
A	He	P	High electronegative
B	F	Q	Most electropositive
C	Rb	R	strongest reducing agent
D	Li	S	Highest ionisation energy

Helium (He) 1s2   $\to$Highest ionisation  energy due to noble gas in nature. 
Fluorine $\text{ (F) }1{\mathrm{s}}^2,2{\mathrm{s}}^{2}2{\mathrm{p}}^3\to$High electronegativity in nature due to small size and —1 oxidation state. 
Rubidium (Rb)  $\to$Most electronegative element due to large atomic size.
Lithium (Li)  $\to$Strongest reducing agent due to small size and positive oxidation state (+1)