The correct answer is A. 40.00%.
Dividend yield is a measure of the return on a stock based on the annual dividend per share divided by the current market price per share. It is expressed as a percentage.
In this case, the dividend per share is Rs 20 and the current market price per share is Rs 50. Therefore, the dividend yield is 20/50 = 40%.
Option B is incorrect because it is the dividend per share, not the dividend yield.
Option C is incorrect because it is the percentage increase in the dividend per share, not the dividend yield.
Option D is incorrect because it is the current market price per share, not the dividend yield.