Which of the following statements is an opinion based on prediction?
a. next week’s math test will be easy.
b. most students dislike taking tests.
c. mrs. turner’s math tests are usually hard.
d. we have a math test next week.

'a' is based on prediction. It's a future situation.The test will be next week and the students hope it will be easy

Refute it, showing why it is mistaken—an apparent but not real problem; acknowledge its validity or plausibility, but suggest why on balance it's relatively less important or less likely than what you propose, and thus doesn't overturn it; concede its force and complicate your idea accordingly—restate your thesis in a more exact, qualified, or nuanced way that takes account of the objection, or start a new section in which you consider your topic in light of it. this will work if the counterargument concerns only an aspect of your argument; if it undermines your whole case, you need a new thesis.