Context: Poland's successive kings granted privileges to the nobility at the time of their election to the throne (the privileges being specified in the king-elect's Pacta conventa) and at other times in exchange for ad hoc permission to raise an extraordinary tax or a pospolite ruszenie.

Question: When did kings grant privileges to the nobles?
Answer: at the time of their election to the throne

Question: What specified the kings privileges?
Answer: king-elect's Pacta conventa

Question: What was also in exchange during he election of the throne?
Answer: ad hoc permission to raise an extraordinary tax

Question: What did nobles get in from the king during election?
Answer: privileges