Agree or disagree? The importance of a team leader

So I was looking around the office for something to blog about today and came across the book, “100 Things you Need to Know: Best People Practices for Managers & HR.”  The book is divided into a 100 “mini sections” each starting off with a multiple choice question.  I read through many of them and found myself questioning the answers but this particular one stood out the most.  Number 56.

Question: What makes the least difference in team effectiveness?

a. Teams managing talent and skill acquisition themselves

b. The personality and style of the team leader

c. The net functional skills of the team to do the work

d. The absolute number of talented individuals on the team

e. Organizational support for the team

The answer? B. The personality and style of the team leader makes the least amount of difference in team effectiveness.

Question to the reader: Do you agree or disagree with the answer? What is the importance of a leader on team effectiveness?