Who has won gold medal in the 2016 Rio Olympics men’s singles tennis tournament?
[A]Kei Nishikori
[B]Andy Murray
[C]Juan Martin Del Potro
[D]Novak Djokovic

Andy Murray
Andy Murray, a British professional tennis player, has won the gold medal in the 2016 Rio Olympic men’s singles tennis tournament by defeating Argentina’s Juan Martin Del Potro in final by 7-5, 4-6, 6-2, 7-5. With this, Murray successfully retained his title as Olympic champion and became the first in the history of the sport to win the prize back to back.