This one took a toll!
So basically, as someone rightly pointed out, this is an INFERENCE question - this understanding solves half of your question.
Trick to identify :
Of the following claims, which is most strongly
supported by the statements given?
Had they asked, which statement supports the claim made in the argument, it would have been a strengthen question.
Coming to the options :
A. At least some people observed during the study had an increase in blood calcium levels during the ten-year period.
NO : We do not know what caused the increase in the blood calcium levels. Never assume, unless specified.
B. People with the hereditary disorder are at no greater risk of developing laryngeal polyps than are people with low blood calcium levels who do not have the disorder.
NO : Once again, this has absolutely no relation to the argument being made.
C. The amount by which the researchers overestimated the likelihood of developing polyps decreased after the first five years of the study.
NO : It could be false if the researchers failed to learn from their mistakes and continued to make estimates that were flawed in the same way.
D. The percent of patients in the study with laryngeal polyps consistently increased over the ten-year period.
NO : The increase in the number of patients has got nothing to do with predicting the likelihood of all/some/none of them contracting the disease.
E. Prior to the end of the study, the researchers had reason to believe that at least some of their predictions had been overestimates.
YES: Makes sense, the argument clearly states "
they almost universally overestimated the likelihood," which means some sort of a fact/error in prediction or a result made them believe about the over estimation.