Final answer:
The term lability defines 'emotional instability,' indicating a tendency for rapid and unpredictable mood changes. It's associated with high neuroticism in Eysencks' personality theory.
Step-by-step explanation:
The term lability is used to define emotional instability in terms of mood-associated behavior. This refers to how susceptible an individual's emotions are to change, demonstrating inconsistency in mood. According to Eysencks' theory, this would be the opposite of someone who scores low on neuroticism, which is characterized by emotional stability.
In contrast, someone who scores high on neuroticism tends to display greater emotional lability, experiencing frequent mood swings and intense emotions. So, in the context of the student's question, the correct answer is C) Emotional instability, indicating a temperament that can shift rapidly and unpredictably.