Explanation:

El Salvador became the first country in the world to adopt bitcoin as legal tender after the country’s Congress has recently approved President Nayib Bukele's proposal to embrace the crypto currency.

• The use of bitcoin has been touted for its potential to help Salvadorans living abroad to send remittances back home.
• In practice, El Salvador does not have its own currency and the U.S. dollar will also continue as legal tender.

Hence option 4th is correct.