Question: Mention the year span in which Edward Heath became head authority of the Member of the 43rd Parliament of the United Kingdom besides the reason for his tenure quit.
SPARQL (Wikidata): SELECT ?value1 ?value2 WHERE { wd:Q128967 p:P39 ?s . ?s ps:P39 wd:Q41582608 . ?s pq:P2715 ?value1 . ?s pq:P1534 ?value2 }