Which statement about extended access lists is true?

Which statement about extended access lists is true?
A . Extended access lists perform filtering that is based on source and destination and are most effective when applied to the destination
B . Extended access lists perform filtering that is based on source and destination and are most effective when applied to the source
C . Extended access lists perform filtering that is based on destination and are most effective when applied to the source
D . Extended access lists perform filtering that is based on source and are most effective when applied to the destination

Answer: B