Question:
Which position did Jordi Sànchez i Picanyol hold in Sep, 2019?

Context:
 Jordi Sànchez i Picanyol holds the position of president of the Assemblea Nacional Catalana from May, 2015 to Nov, 2017. 
 Jordi Sànchez i Picanyol holds the position of Member of the Catalan Parliament from Jan, 2018 to May, 2019. 
 Jordi Sànchez i Picanyol holds the position of chairperson from Jan, 2019 to Jan, 2020. 
 Jordi Sànchez i Picanyol holds the position of Member of the Congress of Deputies from May, 2019 to Sep, 2019. 
 Jordi Sànchez i Picanyol holds the position of director from Jan, 2001 to Jan, 2010.

Answer:
chairperson