Which of the following has the highest percentage of ionic character in its bonding?

A Ketelaar triangle showing a plot of average electrongativity (chi_(mean)) against electronegativity difference (Deltachi) can be used to classify the bond type for binary compound. Which of the following compounds has highest percentage of ionic character ?

Which of the following bond has highest enthalpy

Which possesses highest percentage of ionic character

Which of the following has the highest ionic radius?