It is a matter of gratification for me that he has turned a new leaf. A. begun a different mode of life B. started using his intelligence C. proved to be a worthy person on his job D. accepted the new job that was offered to him E. decided to use a different strategy to solve the problem

The correct answer is A. begun a different mode of life.

The phrase “turned a new leaf” means to start a new life, to change one’s ways, or to reform oneself. In this case, the speaker is expressing gratification that the person has changed their ways and is now living a different life.

Option B is incorrect because it does not mean to start a new life. Option C is incorrect because it does not mean to change one’s ways. Option D is incorrect because it does not mean to reform oneself. Option E is incorrect because it does not mean to start a new life.