Suppose you survey a population of U. S. married adults about their sexual activity. You should expect that couples in which of the following age groups will report having sex most frequently?
◦ couples in their 20s and 30s
◦ couples in their 40s and 50s
◦ couples in their 60s and 70s, after the children have left home
◦ None of the couples reported having sex more frequently, since sexual frequency is unrelated to age.