A select c.nome from tb_cliente c where exists ( select 1 from tb_emprestimo e where e.id_cliente = c.id_cliente )
B select c.nome from tb_cliente c where id_cliente = all ( select id_financeira from tb_emprestimo )
C select c.nome from tb_cliente c where not exists ( select id_financeira from tb_financeira except select e.id_financeira from tb_emprestimo e where e.id_cliente = c.id_cliente )
D select distinct c.nome from tb_financeira f natural join tb_emprestimo e full join tb_cliente c on c.id_cliente = e.id_cliente
E select distinct c.nome from tb_financeira natural join tb_emprestimo natural join tb_cliente c