Question: what us the protype aircraft model with the lowest wingspan whose series is douglas M?
Paraphrase: Which Douglas M series aircraft model has the shortest wingspan?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q15126161 . ?ent wdt:P2050 ?obj . ?ent wdt:P179 wd:Q3714634} ORDER BY ASC(?obj)LIMIT 5 
Answer: Douglas M-1