Bond polarity of a diatomic molecule is because of

Among the following,the pairs of elements having approximately the same electronegativity values are:
$I$. $H$ and $P$
$II$. $Be$ and $Al$
$III$. $N$ and $Cl$
$IV$. $C$ and $P$

Which of the following elements has the highest electronegativity?

Assertion : Electron affinity refers to an isolated atom's attraction for an additional electron while electronegativity is the ability of an atom of an element to attract electrons towards itself in a shared pair of electrons.
Reason : Electron affinity is a relative number and electronegativity is experimentally measurable.

The correct option with respect to the Pauling electronegativity values of the elements is

Going from fluorine to chlorine,bromine and iodine,the electronegativity