A、For the sake of decoration. B、To show their male dominance. C、For self-protection. D、To attract animals in different sex. B

If winning is everything, British scientists have some advice: Wear red. Their survey shows competitors were more likely to win their contests if they wore red uniforms or red body armor.
    Across a range of sports, people find that wearing red is consistently associated with a higher probability of winning. Red coloration is associated with aggression in many animals. Often it is sexually selected so that scarlet markings signal male dominance.
    Similarly, the color’s effect also may subconsciously intimidate opponents in athletic contests, especially when the athletes are equal in skill and strength, the researchers suggest.
    In their survey, the scientists analyzed the results of four combat sports at the summer games. In those events, the athletes were randomly assigned red protective gear and other sportswear.
    Athletes wearing red gear won more often in 16 of 21 rounds of competition in all four events.
    The effect was the same regardless of weight classes, too: 19 of 29 classes had more red winners, and only four rounds had more blue winners.
    The red effect also might come into play in team sports.
    They found that five football teams scored more goals and won more often when they wore shirts that were predominantly red, as opposed to blue or white shirts.
    Scientists don’t precisely know how wearing red might give athletes an advantage. But the color delivers implicit messages of vigor and danger. When people get angry, their faces turn red. It’s also a reason why stop signs are red.