Final answer:
The distribution from Longhorn Company is treated as a $0 dividend with a $100,000 tax-free return of basis and $200,000 capital gain for the shareholder.
Step-by-step explanation:
In this scenario, Longhorn Company distributed $300,000 to its sole shareholder when the accumulated E&P at the beginning of the year was negative $200,000, and the current E&P for the year was $100,000. The treatment for the shareholder would be Option C: $0 dividend, $100,000 tax-free return of basis, and $200,000 capital gain. The initial $100,000 of the distribution is a return of the shareholder's basis in the stock, and since the remaining distribution exceeds the current E&P, the excess $200,000 is treated as a capital gain.