Which of the following statements concerning valuation ratios is correct without limitations? Select one: O A. In general, valuation ratios help investors assess the market value of a firm. O B. Valuation ratios are in particular intended to make intra-country and intra-time comparisons of firm valuations, not to make intra-industry comparisons. C. In order to achieve a reasonable assessment of a firm's valuation, one must always relate a firm's market value to its net income. D. The price-to-earnings ratio relates a firm's book value of equity to its net income.