Which of the following is a valid SQL statement?

a$.$ SELECT $*$ WHERE amid $=$J$100$ FOR UPDATE;

b$.$ INSERT INTO homeworkl$0$ VALUES $($SELECT $*$ FROM acctmanager$)$;

c$.$ DELETE amid FROM acctmanager;

d$.$ rollback;

e$.$ all of the above

Explain in detail with actual examples and screenshots of the outputs to prove.