A Ltd pays $90,000 to acquire 90% of the shares of B Ltd on 1 January 20x4 when B Ltd was incorporated with share capital of $100,000 (comprising 100,000 ordinary shares at $1 each). On 1 January 20x8, when the fair value of B Ltd's identifiable net assets was represented by share capital of $100,000 and retained profit of $40,000 and A Ltd's shares are traded at $1.50 per share, A Ltd sells 80% of the shares (and retains 10% of the shares) of B Ltd for cash consideration of $120,000. The 10% shareholding in B Ltd is accounted for as "held-for-trading" securities and the shares are traded at $2 per share on 31 December 20x8. In this case, the fair value gain in A Ltd's consolidated financial statements is:

1. $6,000.

2. None of the listed choices.

3. $10,000.

4. $5,000.

$0.