Retained Earnings Calculation Formula Steps:

• Start with opening retained earnings on 1 January 2018: $68,000.
• Add net profit for 2018: $68,000 +$31,000 = $99,000.
• Calculate dividend: 20,000 shares × $0.50 par value =$10,000 share capital; 9% × $10,000 =$900.
• Subtract appropriations: $99,000 -$900 dividend - $12,000 transfer =$86,100.

Not enough information: Calculated closing retained earnings of $86,100 does not match any option, making the question ambiguous.

Final answer: Not enough information.