Choose the correct option to close a letter written to a friend:

Yours affectionately

The correct answer is Option (4) → Yours affectionately

Explanation:

• "Yours truly" is a formal closing typically used in business letters.
• "Yours obediently" is overly formal and usually reserved for letters addressed to authority figures.
• "Yours sincerely" is a semi-formal closing often used in professional or formal correspondence.
• "Yours affectionately" is a warm and friendly closing suitable for letters to friends or close acquaintances.

Therefore, "Yours affectionately" is the appropriate closing for a letter written to a friend.