Which of the following is true about what economists have found regarding the impacts of immigration on native workers' wages?
a. While there is evidence that immigrant populations negatively impacted wages for native born workers at the turn of the 20th century, by the end of the 20th century no such relationship can be found.
b. Throughout history, immigrant populations have led to increased wages and more jobs for native workers.
c. Throughout history, immigrant populations have led to decreased wages and fewer jobs for native workers.
d. Historically, immigrant populations led to increased wages, however in contemporary America immigration has negative impacts on the wages of the native population.