Candice, Juana, Milly, and Olga are close friends who spend a lot of their time together discussing problems they have with their parents, their siblings, and their boyfriends. A negative outcome of this co-rumination is that

they may experience increased depression and anxiety.

Explanation:

Co-rumination can be defined as the condition in which one continues to rehash their problems over and over again without coming to a solution. This discussion is usually done in a peer group, in which they extensively discuss their problems and focus on negative feelings. Such discussions can have a bad effect on health such as depression and anxiety, and even dangerous for relationships.

In the given case, Candice, Juana, Milly, and Olga are close friends who discuss the problems they have with their closed ones (parents, siblings, and boyfriends) repeatedly. These discussions will have repercussions on their health as repeatedly discussing problems can lead them to depression and anxiety.

So, the correct answer is that it can lead them to increased depression and anxiety.