To which senator did military unit VMF-155 belong?
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/ontology/militaryUnit> <http://dbpedia.org/resource/VMF-155>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Senator>}
VMF-155