Considering “Indifference analysis”, which indicates the level of operating income (or earnings before interest and tax, EBIT) where EPS (earnings per share) are equal whether the firm uses debt or equity, we can conclude that the following holds:

Beyond the indifference point, more debt will maximize EPS

Beyond the indifference point, more equity will maximize EPS

Using more debt makes EPS more volatile

Using more equity makes EPS more volatile

Both a) and c) are true