What is {relative} of {Theodor Mommsen} that is {type of kinship} is {grandson} ?
Who is Theodor Mommsen's grandson?
SELECT ?obj WHERE { wd:Q25351 p:P1038 ?s . ?s ps:P1038 ?obj . ?s pq:P1039 wd:Q11921506 }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q25351> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1038> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P1039> <http://wikidata.dbpedia.org/resource/Q11921506>
} 

Give me the name of Theodor Mommsen's grandson?