HELP. PLEAEEE THIS IS DUE IN 10 MINUTES

The Soviet Union’s reaction to the 1968 "Prague Spring" in Czechoslovakia was to:

a
Withdraw Soviet troops from Eastern Europe
b
Send Soviet troops and tanks to occupy Czechoslovakia
c
Bring the matter to the attention of the United Nations
d
Have a summit meeting with Western leaders
e
Permit limited political and economic reforms in Czechoslovakia