ПОМОГИТЕ ПОЖАЛУЙСТА ДАЮ 20БАЛЛОВ!!!
1)This is a boy ____ had an accident *

-who
-which
-what
2)Yesterday I saw a car ____ was really old. *

-who
-which
-what
3)The man ____ house is on fire, is crying now. *

-whose
-whom
-what
4)My friend's cat, ___ is already 15, looks nice. *

-who
-which
-what