Question

Scientists earlier believed that the lowest measurable temperature is the freezing point of ice. However, modern scientists believe that temperatures below the freezing point of ice can also exist. What best accounts for these different opinions?

scientists propose contradictory ideas to include all possibilities

scientists come up with different hypotheses without enough evidence

scientists propose different ideas to avoid repetition of scientific knowledge

scientists having different interests may interpret the same data in different ways

Answer 1

Well, first of all, the premise is wrong. Scientists never believed the lowest possible temperature is the freezing point of water. You'd have to be an idiot to think that, once having lived through a solid European winter.

And the best answer to the question is that distinctions like this can arise from the principle of parsimony (also called Occam's Razor), where scientists routinely construct the simplest and broadest possible theory to explain facts, because this tends to lead to rapid progress. For example, on observing a single black sheep, a scientist would immediately propose the hypothesis: "All sheep are black." The reason this is useful is that it's the simplest explanation for the observation (satisfying the principle of parsimony) and, because it is very broad, it is very easy to test -- you just need to find another sheep. If you do, and find the second sheep is white, the next step would be to propose "All sheep are either black or white." Now you find a third sheep...and one we go. By repeated empirical tests, we eventually arrive at the simplest theory that fits all the evidence. That's the best we can.

If we're forced to select among your answer choices, the best answer is probably "scientists come up with different hypotheses without enough evidence" because that emphasizes the role of evidence in the change: if you had no evidence that temperatuers below 0C were possible, you might well suggest it was not, and someone who had evidence would realize it was -- and that would explain the difference. It's not very well stated in this answer choice, but oh well.