Final answer:
Tammy's personality type is Neurotic, as she experiences negative emotions like insecurity and anxiety, which are characteristic of neuroticism according to the Five Factor Model.
Step-by-step explanation:
Given the descriptions provided that Tammy is always insecure, anxious, guilty, and moody, the type of personality she possesses is C) Neurotic. In psychology, neuroticism is one of the Five Factor Model personality traits and it refers to the tendency to experience negative emotions and emotional instability. Individuals characterized by high levels of neuroticism often feel anxious and may exhibit moodiness, guilt, and insecurity.