Answer: Selection bias
Explanation:
Selection bias is defined as the process in which individual or group of individual are analyzed for selection process by lacking randomization property .This process displays that selected sample of individuals is not similar representative of major interest population.
According to the question,the systematic difference that occurs in selected group for experiment as per their last name is displaying that selected group does not represent interest population that is causing systematic error.Thus, this situation describes about selection biasing.
Adopting the US dollar as "legal tender" in Argentina and in other countries is a specific currency policy that is called "dollarization." This fixed currency policy uses the currency of a foreign country that is believed to be more stable because of previous domestic currency problems such as hyper inflation. The goal is to stabilize the country's economy by substituting another currency for their own currency.
This would be called aptitude or achievement
