The fiduciaridade of the money comes from the reliability of the population in the government, which was possible thanks to the institutionality that arose with the development of the capitalism.
At first, all money should be backed up in some precious metal, usually gold. That way, at any time, a citizen could convert his currency to gold, according to the quote. This posed a problem for the issuance of the currency, since the Government would need to obtain increasing reserves of precious metal.
Of course, gold ballast was not a sustainable process, and ballasting started to be exchanged for the fiduciary currency, that is, not convertible, but guaranteed by the word and the institutionality of the Governments.
In the US, President Richard Nixon canceled the convertibility of the dollar in gold in 1971, leaving the exchange rate fluctuating and wiping out any paper ballast. In other words, the government came to have the power to control the value of money.
Therefore, the first alternative is correct (A).
