Gordon allport was the first to determine that: a. personal traits can be described according to two primary variations in extraversion and neuroticism. b. environment has a profound influence on personality traits. c. a model with five individual differences does the best job of describing main personality traits. d. certain consistencies in a person's behavior may reflect some sort of inner psychological quality.

The right answer is d. Certain consistencies in a person's behavior may reflect some sort of inner psychological quality. Based on these observations he developed a theory of personality based on personality traits. He described these traits as inherent characteristics of the people observable in certain characteristic behaviors. He considered that all people had these traits to a greater or lesser extent and this determined the personality.

I hope my answer can help you.