Kasyanov was sacked by Putin in February 2004, after he had become critical of the Kremlin's politically motivated legal attack on the Yukos oil giant and its owner, billionaire Mikhail Khodorkovsky.
The Kremlin is a name for Russia's central government.
This is not explicitly stated in the text, but a basic knowledge of Russian players and politics would make these statement easy to judge as correct. I think the system just didn't want to make assumptions without text evidence.
( z1 name :domain ( z2 government-organization :name ( z3 name :op "Kremlin" ) :ARG0-of ( z4 govern :ARG1 ( z5 country :name ( z6 name :op "Russia" ) ) ) :mod ( z7 center ) ) )