One of the most useful social conventions is money, whose universality across societies is matched only by language. ...

Ravi on November 12, 2020

@Mazen,

Let's look at A and C.

We're trying to pick an answer choice that guarantees the truth of the
conclusion. The correct answer makes the argument valid.

C doesn't work because we want to prove that money (which is an
invention) was invented independently. Knowing things that aren't
inventions does not help us to prove the conclusion, so this is out.

With A, we know that all societies have money from the stimulus. A
tells us that some societies are so isolated that they are not
influenced by any other societies (think of a tribe in the Amazon
rainforest). If this is true, then the isolated societies (which we
already know from the stimulus have money) must have invented money on
their own. This proves the conclusion, making the argument valid.
Thus, it's the correct answer choice.

Hope this helps!

Fiallos.Luis11 on March 9, 2021

@Ravi

For C, Is it also okay to conclude that it was never established that language was not an invention and that's another reason why C is wrong?

As to A, I picked that answer taking into consideration the language portion of the stimulus. The stimulus established that the other thing "so universal" as money is language, so if these societies were isolated, it is possible they could not communicate with one another (through language) and therefore, the invention of money occurred independently. Let me know if this logic is correct is please.