想问一下一道prep12里的题目

夥颐

Increases in the level of high-density lipoprotein (HDL)in the human bloodstream lower bloodstream cholesterol levels by increasing the body's capacity to rid itself of excess cholesterol. Levels of HDL in the bloodstream of some individuals are significantly increased by a program of regular exercise and weight reduction.

Which of the following can be correctly inferred from the statements above?

• AIndividuals who are underweight do not run any risk of developing high levels of cholesterol in the bloodstream.
• BIndividuals who do not exercise regularly have a high risk of developing high levels of cholesterol in the bloodstream late in life.
• CExercise and weight reduction are the most effective methods of lowering bloodstream cholesterol levels in humans.
• DA program of regular exercise and weight reduction lowers cholesterol levels in the bloodstream of some individuals.
• EOnly regular exercise is necessary to decrease cholesterol levels in the bloodstream of individuals of average weight.
  

这这题的D选项，原文中提到HDL是能够[color=rgba(0, 0, 0, 0.8)]increasing the body’s capacity to rid itself of excess cholesterol；我想问一下原文提到的是去促进身体消除excess chol的能力，那如果我身体里的chol已经很低了，不excess，是一个正常的水平，是不是我regular 锻炼就不会使我的chol降低了