Question: What is the cause of death of Joseph P. Kennedy Ii's father?
Sentence (from "Robert F. Kennedy"): Robert Francis Kennedy (November 20, 1925 – June 6, 1968) was an American politician and lawyer who served as the 64th United States Attorney General from January 1961 to September 1964, and as a U.S. Senator from New York from January 1965 until his assassination in June 1968.
Relevant evidence: No