Answer: Electronegativity increases across a period.
Step-by-step explanation:
Electronegativity is defined as ability of an atom to attract shared pair of electrons in a bond toward itself.
Electronegativity increases across the period because when we move across the period from left to right numbers of protons and electrons are increased. By increase in number of protons ,nuclear charge also increases due to which electrons present in an atom are strongly attracted towards the nucleus. And due to presence of strong nuclear charge shared pair of electrons in a bond are also attracted towards nucleus of an electronegative atom.