Which of the following is most electronegative?

The covalent compound $HCl$ exhibits ionic character because:

Consider the following.
Statement-$I$ : The order of electronegativity of $B, Al, In, Tl$ is $B > Tl > Al > In$.
Statement-$II$ : Boric acid is a weak protonic acid.
The correct answer is

In which molecule does the chlorine atom have a positive partial charge?

For $AB$ bond,if percent ionic character is plotted against electronegativity difference $(X_A - X_B)$,the shape of the curve would look like. The correct curve is:

Arrange the following bonds in order of increasing ionic character: $C-O, C-N$ and $C-C$. Give reasons.