Answer:
Amir's basis is $0, so he/she is no longer a shareholder, and must pay taxes only for the $3,500 capital gain.
Step-by-step explanation:
Accumulated earnings and profits = $0, so it should not distribute dividends. What probably happened is that Indigo is repurchasing Amir's stocks:
Amir's gain/loss on the distribution = $18,500 cash - $15,000 basis = $3,500 gain
So now Amir's basis is $0, so he/she is no longer a shareholder, and must pay taxes only for the $3,500 capital gain.