Which of the Following BEST Describes the Findings of Researchers

Which of the following BEST describes the findings of researchers studying insomnia and aging?

A) they consistently find that people over age 65 experience insomnia more frequently than other age groups
B) they consistently find that people over age 65 experience insomnia less frequently than other age groups
C) they consistently find that the rates of insomnia for people over age 65 are similar to other age groups
D) they sometimes find that people over age 65 have lower rates of insomnia than those under age 50