Which statement best summarizes the support for trait theories in identifying universal distinguishing attributes of leaders?

a$.$ findings on traits as a basis for explaining universal leader effectiveness have found no solid conclusions

b$.$ trait theory studies have tended to conclude that there are strong implications for training and development rather than selection

c$.$ trait studies have identified physical attributes as being more important to leadership than personality or abilities such as intelligence

d$.$ when looking at physical attributes, height has been the indicator of a leader attribute.