Which part of the following sentence is predicate?
Nolan, who is known for keeping details of his productions secret, strove to ensure secrecy for "Interstellar".
1
known for keeping details of his productions secret
2
keeping details of his productions secret
3
strove to ensure secrecy for "Interstellar"
4
who is known for keeping details of his productions secret, strove to ensure secrecy for "Interstellar