Answer: Option (a) is the correct answer.
Step-by-step explanation:
It is known that when we move across a period from left to right in a periodic table then there will be decrease in size of elements. This is because of addition of electrons into the same sub-shell.
Whereas when we move down a group then there occurs an increase in size of atoms due to addition of new sub-shells.
As electronegativity is the ability of an atom to attract an electron towards itself. Hence, smaller is the size of an atom more will be the ability of its nucleus to attract a proton towards itself. As a result, higher will be its electronegativity.
For example, fluorine is the most electronegative element present in the periodic table.
Thus, we can conclude that upper right area of the periodic table has the highest electronegativities.