An examination of corruption provides the basis for rejecting the view that an exact science of society can ever be constructed. As with all other social phenomena that involve deliberate secrecy, it is intrinsically impossible to measure corruption, and this is not merely due to the fact that social science has not yet reached its goal, achievable to be sure, of developing adequate quantifying techniques. If people were ready to answer question about their embezzlements and bribes, it would mean that these practices had acquired the character of legitimate, taxable activities and had ceased to be corrupt. In other words, corruption must disappear if it is to be measurable.

Which one of the following most accurately states a hidden assumption that the author must make in order to advance the argument above?
(A) Some people believe that an exact science of society can be constructed.
(B) The primary purpose of an exact science to quantify and measure phenomena.
(C) An intrinsic characteristic of social phenomena that involve deliberate secrecy is that they cannot be measured.
(D) An exact science of social phenomena that involve deliberate secrecy cannot be constructed.
(E) An exact science can be constructed only when the phenomena it studies can be measured.

Please explain your answers.

Can you please explain your reasoning?

An assumption is something that must be true in order for the conclusion to hold valid.

The conclusion is that an exact science can never be constructed. Why? because you can't measure it; why can't you measure it? because it's secret; unless it becomes open you will not be able to meaure it BUT if it becomes open it ceases to be something which you would call corrupt - the underlying theme is that a thing must be measurable in order for it to be called an exact science. This is exactly the point stated in choice E.

I picked E too. I agree with dwivedys reasoning... Good job.