question: Which production company acquired M1 , M2 , M3 , and M4 and was acquired by a company
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.production_company .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company ?x1 .
  ?x0 ns:organization.organization.companies_acquired/ns:business.acquisition.company_acquired M1 .
  ?x0 ns:organization.organization.companies_acquired/ns:business.acquisition.company_acquired M2 .
  ?x0 ns:organization.organization.companies_acquired/ns:business.acquisition.company_acquired M3 .
  ?x0 ns:organization.organization.companies_acquired/ns:business.acquisition.company_acquired M4 .
  ?x1 a ns:business.employer
  }