OV1 reading mixed practice 1

Hi, dear teachers, long time no see, how are you?

The Reading:

Although it is intuitively clear that an increase in antipredator behavior lowers an animal’s risk of predation when predators are present, such benefits are not easily demonstrated. One study that did so found that well-fed guppies are more alert for predators and are consequently less likely to be killed than are their hungry counterparts, which feed with greater intensity. It is also well documented that a decrease in activity lowers an animal’s risk of predation by reducing the probability of being detected or encountered by a predator. This effect was convincingly demonstrated by a study in which it was found that partially anesthetized tadpoles were less likely to be captured by dragonfly larvae than were unanesthetized tadpoles.

In the context indicated, “demonstrated” (line 3) most nearly means

A explained
B presented
C shown
D protested
E justified105

C is the answer, while I was thinking that since scientists did two “experiments”, they were attempting to “demonstrate(justify, vindicate)” the “intuitively clear (but not verified) description” of the first sentence. Could somebody help out? I am pretty baffled. Thanks a lot ^^

The test appears to be skewed if it indicates that ‘C’ is the only possible answer.

To demonstrate = to show, but it can also be used to indicate ‘to present’. (to show or offer for others to view).

Yes, I agree. The first thing I had done was to eliminate B and C since they, to my knowledge, basically means the same. I’ve looked into some dictionaries, finding that “demonstrate” does have the meaning of E (MW dictionary: to prove or make clear by reasoning or evidence). So maybe it’s just the question of the language it self, that we don’t usually use “demonstrate” to mean “prove”?

Thanks again~

I don’t understand why you eliminated C. That is one of the correct possibilities, and the most usual synonym for ‘demonstrate’.

Ok, I’ll think it over. Thank you anyway.