Helpp i have an official tmw

hello,
so I'm struggling with this question so please help me that would be appreciated !
the answer to a is (b)
and the answer to b is (d)
thanks in advance !

For (a), you need the difference in electronegativity to be the maximum. That way, the distribution of charge will be most asymmetrical.

For (b), you need the difference in electronegativity to be the least.

As for (b), the opposite is true, actually. Think about it this way. A covalent bond having 'ionic character' means that the difference between the charges of both bonded atoms has to be greater; one needs to be more positive and the other needs to be more negative. Hence, the difference in electronegativity between the atoms needs to be the greatest.

I've actually just finished doing and marking this paper an hour ago, and the marks scheme confirms this.

But for (b) the question is which compound is most ionic? None of the options have a covalently bonded molecule. Polar covalent bonds are not relevant.

Edit: Oops, I just realised what I typed earlier. You're right about the difference in electronegativity (although covalent bonds are not involved here)

You're right, actually! They're all ionic bonds. I never noticed that while doing the question. Regardless, to be 'more ionic' means to have a greater difference in electronegativity.