The newly elected chairman has been … into office.

Analyze the question: We need the word that correctly fills the gap in "The newly elected chairman has been ......... into office." The key is the preposition "into" and the verb that collocates with it.

Explain the concept: This tests collocation, meaning words that naturally go together. Some verbs commonly take "into office":

• sworn into office: used when someone takes an oath (presidents, governors, judges)
• installed in office / installed as chairman: "installed" usually takes "as" or "in", not "into"
• inaugurated into office: this is also used, but "inaugurate" is more often used for a ceremony that begins a term or opens a project ("inaugurated as president")
• admitted into a school, hospital, or club, not an office

Step by step:

1. "Admitted" fits schools, hospitals and societies, so C is out.
2. "Installed" usually goes with "as" or "in", so B is weaker.
3. "Inaugurated" is possible, but the standard phrase with "into office" is "sworn into office". It is the fixed, most idiomatic collocation.
4. "Inaugurated" is often seen as a distractor because it is close in meaning, but the question asks for the word that best completes the sentence.

I should also be honest that D is arguable, since "inaugurated into office" does appear in some Nigerian usage.

Answer: A. sworn

Tip: Memorize the fixed phrase "sworn into office". When a question involves taking an oath of office, "sworn" is usually the best choice. Also remember: admitted goes with schools or hospitals, and installed goes with "as" or "in".