question: President Kennedy sent a letter on April 20 , 1961 to who about the US 's space program ?
answer: Vice President Lyndon B. Johnson
turker_answer: President Kennedy sent a letter on April 20 , 1961 to Vice President Lyndon B. Johnson
rule-based: President Kennedy sent a letter on April 20 , 1961 to vice President Lyndon B. Johnson about the US 's space program .