Answer the following question: Extract the answer to the following question from the movie plot. If the question isn't answerable, please output "Can't answer". Question: who decides to work on their marital problems? Title: Blame it on Rio Movie plot: American businessman Victor (Joseph Bologna) and British-born entreprenour Matthew (Michael Caine) are best friends who work for a major corporation in Sao Paulo, Brazil. Both are having problems in their marriages: Victor's wife wants to divorce him, while Matthew has no idea what is wrong and is baffled and irritated by the decision of his wife Karen (Valerie Harper) to take her vacation separately from her husband and daughter.The men decide to holiday in Rio de Janeiro. With them are their teenage offspring: Matthew's 15-year-old daughter Nikki (Demi Moore) and Victor's 16-year-old daughter Jennifer (Michelle Johnson). They rent a beautiful vacation home overlooking the city with a somewhat taciturn and disapproving housekeeper who treats all of them badly and avoids talking to any of them.At the beach, Jennifer is told by her father to cover her bare breasts but refuses, instead dragging her father and Nikki into the water to play. Matthew does not join them and seems uncomfortable with the partial nudity displayed by Jennifer and other topless women on the beach.A few nights later, Matthew gets drunk with the amorous Jennifer during a Brazilian wedding, where she discloses to him that she has had a "crush" on him since she was a child. After having sex on the beach, they embark on a secret sexual relationship.Victor becomes furious when he finds out that there is an "older man" in his daughter's life when he sneaks a peak at her diary, and he sets out to hunt down the mystery man. He expects Matthew to help. Matthew is reluctant to lead Victor on a wild goose chase but goes through with it out of fear to what Victor might do to him. In private, Matthew tries to talk to Jennifer to end their secret affair before her father finds out, but she is determined to never give him up.Meanwhile, Nikki learns that Jennifer is involved with her father, but despite her protests, Jennifer (who by this point has fallen in love with Matthew) refuses to end it.Victor and Matthew's persuit of Jennifer's "older man" leads...
Answer:
Karen and Matthew