The more depressed Betty feels, the more easily she remembers many of the sad events in her life. This best illustrates:

Answer:Mood-Congruent Memory

Explanation:Mood-Congruent Memory refers to how we tend to store memories about particular events along with the emotions associated with those memories. When we are happy we are likely to remember other happy memories or events and also when we are experiencing sadness we are likely to have other sad memories being brought up into our mind. This means we are more likely to experience certain similar emotions when a same situation occurs, similar to what we have stored in our memories.

This is why when Betty is sad more sad memories or events are brought back into her mind.