"Grandma Is 65 Years Old, and There's No Sign of Neurocognitive

"Grandma is 65 years old, and there's no sign of neurocognitive disorder," says a friend of yours. Your MOST accurate reply is:

A) "That's wonderful-about a third of people that age do have signs of neurocognitive disorder."
B) "That's wonderful-about 20 percent of people that age do have signs of neurocognitive disorder."
C) "That's wonderful-about 5 to 10 percent of people that age do have signs of neurocognitive disorder."
D) "That's wonderful-about 1 to 2 percent of people that age do have signs of neurocognitive disorder."