The correct answer is B. Rs 15.00.
Book value per share is calculated by dividing the total common equity by the number of shares outstanding. In this case, the total common equity is Rs 996,000,000 and the number of shares outstanding is 50,000,000. Therefore, the book value per share is Rs 15.00.
Option A is incorrect because it is the price per share, not the book value per share. The price per share is the market value of a share of stock, while the book value per share is the accounting value of a share of stock.
Option C is incorrect because it is the price-to-book ratio, not the book value per share. The price-to-book ratio is a measure of how expensive a stock is relative to its book value.
Option D is incorrect because it is the earnings per share, not the book value per share. The earnings per share is a measure of how much profit a company makes per share of stock.