Battulga is known as a former judo champion turned politician — making him an easy figure to remember as Mongolia's President in 2017.
Since the question asks about the "newly elected" president, checking who won the most recent contest among these names is the key.
Since Battulga is the winner of the most recent contest among these names, option 4 is correct.
Hence, the correct answer is Khaltmaagiin Battulga.