Final answer:
Unskilled laborers would most likely have been used as strikebreakers at the turn of the 20th century.
Step-by-step explanation:
The answer to the question is A. Unskilled laborers. Unskilled laborers would have most likely been used as strikebreakers at the turn of the 20th century. Strikebreakers were individuals hired by employers to replace striking workers during labor strikes. Unskilled laborers, who often faced difficult working conditions and low wages themselves, were a cheap source of replacement labor for companies and were used to prevent strikes from being successful.