The correct answer is C. Europeans who could not afford to pay for a trip to America.
Step-by-step explanation:
As colonization began in America, many Europeans wanted to travel to the newly discovered continent and began a new life. However, many of them could not afford the trip to America that was expensive during that time. Due to this, many agreed to become servants of wealthy colonizers that owned land, which was known as Indentured Servitude. This means wealthy colonizers paid the trip for some Europeans and in exchange those Europeans became servants. Additionally, over time this was considered as a type of slavery but servants were free after a certain amount of years of servitude. According to this, indentured servants were mainly "Europeans who could not afford to pay for a trip to America."