question: Q:Which of the following is true about the diagnosis of "osteopenia" or "osteoporosis" in North America and Western Europe
  ? 
  A:Women over age 80 with osteopenia have above average bone mineral density for their age;B:Fewer than 10% of women over age 50 have osteopenia;C:Fewer than 50% of women over age 80 have osteopenia or osteoporosis;D:Osteoporosis is defined as a bone density lower than 2.5 standard deviations below the average for age-matched controls.