Answer:
b. effortful control
Step-by-step explanation:
Children's temperament is composed of three factors: (1) extroversion, characterized by impulsivity, high intensity pleasure, activity level and shyness dimensions; (2) negative affect, defined by the dimensions sadness, fear, anger, discomfort and ability to calm down; (3) effort control, which refers to the dimensions inhibitory control, attention focusing, low intensity pleasure and perceptual sensitivity.
Negative affect and extroversion are associated with reactivity and appear from the earliest stages of development, and can be clearly seen as early as the child's age. Effective control, in contrast, is associated with self-regulation and begins to delineate at the end of the first year, becoming progressively more sophisticated and organized as the child approaches the preschool stage. Thus, despite having a relative temporal stability, temperament develops along the life trajectory.