What are three advantages of adjusting the mark-up code on the page <head> in Community Builder? Choose 3 answers

What are three advantages of adjusting the mark-up code on the page <head> in Community Builder? Choose 3 answers
A . Ability to define iframe settings
B . Optimizing the load times of certain typefaces
C . Optimizing SE by adjusting the SE meta tags for search engines
D . Custom JavaScript blocks
E . Custom, analytics code, such as Google Analytics

Answer: A,B,E