Fill in the blank with the suitable Adverb from the given alternatives.

I met my old friend after 30 years __________.

unexpectedly

The correct answer is Option (4) - unexpectedly

The correct answer is: "unexpectedly" → "I met my old friend after 30 years unexpectedly."

• The sentence suggests that the meeting was not planned or anticipated, so "unexpectedly" is the most suitable adverb.
• "Lastly"  → Means finally or in the last position, which does not fit the context.
• "Firstly"  → Means at the beginning, which is irrelevant here.
• "Arrogantly"  → Describes behavior or attitude, which is not relevant to the situation.