Question:
Which political party did Jacques Piette belong to in Jul, 1975?

Context:
 Jacques Piette is a member of the Socialist Party from Jan, 1969 to Apr, 1990. 
 Jacques Piette is a member of the French Section of the Workers' International from Jan, 1934 to Jan, 1969. 
 Jacques Piette is a member of the French Communist Party from Jan, 1932 to Jan, 1934.

Answer:
Socialist Party