Many slaves were … in the 19th century.

Analyze the question: We need the word that best fits "Many slaves were ......... in the 19th century." The sentence is about slaves being set free from slavery, so we want the word that specifically means being legally freed from bondage.

Explain the concept: This is a vocabulary-in-context question. All four options can sound close, so test each one against the context (slavery, history, 19th century).

Step-by-step solution:

• A. released: This means to let go or set free from confinement (e.g., a prisoner released from jail). It is possible, but it is general and does not carry the historical and legal sense of ending slavery.
• B. empowered: This means to give someone power or authority. It does not mean freeing someone from slavery, so it is wrong.
• C. emancipated: This means to set free from legal, social, or political restrictions, especially slavery. The word is strongly linked to the abolition of slavery (e.g., the Emancipation Proclamation, the emancipation of slaves). It fits perfectly.
• D. relieved: This means to ease pain, worry, or duty, or to take over from someone on duty. It does not fit.

Answer: The best word is emancipated, which is option C.

Tip: Whenever you see "slaves" in a sentence with "freed," think emancipate. Remember: Emancipate = End of slavery. Also note the related word emancipation, which often appears in history-based English questions.