I want to know the answer to the following question:
During which football season did Barcelona win its second treble?
All the background I'm provided with is that "That same year, it also became the first football club ever to win six out of six competitions in a single year, thus completing the sextuple, comprising the aforementioned treble and the Spanish Super Cup, UEFA Super Cup and FIFA Club World Cup.". Is that enough to answer the question?
Answer: no