question: Which producer of M2 was employed by M0 , employed by a film distributor acquired by M4 , and employed by M1
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ns:film.producer.film|ns:film.production_company.films M2 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M0 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
  ?x1 a ns:film.film_distributor .
  ?x1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M4
  }