The documentary about life in the slums was really___________ and was followed by a lot of discussion about how to solve this problem.

Thought-provoking (compund adj): to make thinking serious, thought-provoking

The documentary about life in the slums is really thought-provoking and followed by a lot of discussion about how to deal with this problem.

The remaining answers

Fast-growing (compund adj): to grow fast

Up-to-date (compund adj): updated, trendy, modern

Short-term (compund adj): short term