Can we draw the following hypothesis from the context (see options)? 

Context:

Felipe González Márquez (born March 5, 1942) is a Spanish socialist politician. He was the General Secretary of the Spanish Socialist Workers' Party (PSOE) from 1974 to 1997.

Hypothesis: The PSOE started in the 1950s.
Options are: - Yes. - It's impossible to say. - No.
It's impossible to say