Which of the Following Couples Is Experiencing the Trend Known

Which of the following couples is experiencing the trend known as grey divorce?

A) Amy and Ted, who are in their 40s and have been married 15 years and are divorcing.
B) Donna and Terry, who are in their 50s and have been married for 25 years and are divorcing.
C) Barb and Mark, who are in the 60s and have been married for 10 years and are separating.
D) Denise and Larry, who are in their 60s and have been living common-law for 10 years and are separating.