Final answer:
Gustavo would likely score high on the factor of Conscientiousness in the Five-Factor Model.
Step-by-step explanation:
In the Five-Factor Model, Gustavo's even-tempered and stable nature aligns with the factor of Conscientiousness. Conscientiousness is characterized by competence, self-discipline, thoughtfulness, and goal-directed behavior. Individuals who score high on this factor tend to be hardworking and dependable. This factor is associated with emotional stability and one's ability to remain calm. Given his even-tempered nature, Gustavo would be on the lower end of neuroticism, indicating more stability and resilience to stress, a characteristic of someone with lower levels of neuroticism.
Answer: b) Conscientiousness