Indian Institute of Foreign Trade 2010 Solved Paper

In statement A, blunder mistake is an example of redundancy. It should be either 'He made a blunder' or "He made a mistake".
In statement B, it should be "I have learnt this lesson word for word".
In statement C, it should be "She does not know how to swim".
Only statement D doesn't have any error. Hence, option D is the correct answer.