The statement that most accurately reflects the relationship between reactivity and electronegativity is:
An element will be more reactive if it has a very high or very low electronegativity.
This is because highly electronegative elements (like fluorine) tend to attract electrons strongly, making them more reactive in gaining electrons, while very low electronegativity elements (like alkali metals) readily lose electrons, making them reactive in a different way. Thus, both extremes in electronegativity can correspond to higher reactivity, depending on the context (gaining vs. losing electrons).