When was Buddhism introduced to Japan?

With regard to personality, it appears that: a) there is little consistency of behavior from one situation to the next and little consistency of traits over the life span. b) there is little consistency of behavior from one situation to the next but significant consistency of traits over the life span. c) there is significant consistency of behavior from one situation to the next but little consistency of traits over the life span. d) there is significant consistency of behavior from one situation to the next and significant consistency of traits over the life span.