Learn English – “Changes in” , “Changes of” or “Changes to”

The first implies that you are offering help to someone and want to know if he would allow you to do so. The second implies that the person is looking for something/help and you want to know if you can do something for him. It could be used in situations where you go to your boss's office for something and he may simply say if he can do something for you. They could be used for the same thing in certain situations but they don't mean the same thing.

Since I guessed the right answer when I read the four rewrites of the original sentence, I thought it might be helpful to share my quick analysis of each of the four rewrite options with you.

Rewrite #1 frames the human capacity to correct problems in terms of the likelihood of quickly solving a particular problem once its nature is understood. But the original doesn't speak of likelihoods; it speaks unequivocally of a capability. And it doesn't at all address the question of how quickly a solution is likely to be forthcoming.

Rewrite #2 essentially restates the original statement. The only aspect of this rewrite that seems a bit off is the use of "Hopefully" to introduce the discussion of the human capability to solve identified problems; the original version uses the phrase "On a more optimistic note," which is essentially a heavily padded transition to move from one sentence to another. It's true that "Hopefully" expresses a desire for a good outcome, but it seems to me that "optimistic" expresses something closer to an expectation than to a mere hope. Still, being hopeful and being optimistic are fairly closely related ideas.

Rewrite #3 is obviously a bad choice because it celebrates the idea that people have few identified problems, whereas the original wording indicates that identified problems are the ones that people can overcome.

Rewrite #4 focuses on a specific problem and announces that "we" can solve it. But the original wording is more general and makes a somewhat different claim: that people can solve problems once they have identified them (with sufficient accuracy and clarity, presumably). Although it may seem reasonable to infer that once the particular problem that the monkey economy experiment investigated is understood adequately, people will be able to solve it, it doesn't follow that (1) people have reached the necessary level of understanding of the problem yet, and (2) people can solve the problem now (or in other words, a solution to the problem already exists).

Under the circumstances, rewrite #2 is the most accurate restatement of the original sentence. And in the cramped, airless environment where tests like this one exist, "most accurate" is treated as being equivalent to "correct."