Final answer:
Since HY is a stronger acid than HX, its conjugate base Y- is a weaker base than the conjugate base X-.
Step-by-step explanation:
The weak acid HY is much stronger than the weak acid HX. According to Brønsted-Lowry theory, the strength of an acid is inversely related to the strength of its conjugate base. Therefore, since HY is a stronger acid than HX, its conjugate base Y- would be a weaker base than the conjugate base X-. This is because stronger acids ionize more completely in water, leaving behind a conjugate base that is less inclined to re-associate with a proton. On the other hand, a weaker acid does not ionize as fully, resulting in a conjugate base that is more capable of accepting protons, making it a stronger base.
In this case, the correct statement is B) Y is a weaker base than X-.