Final answer:
The correct answer is option d) Mass arrests and purges occurred.
Step-by-step explanation:
After the assassination of Sergei Kirov in 1934, a series of events unfolded that intensified Stalin's reign of terror. The correct answer to what happened in the short term after Kirov's murder is that mass arrests and purges occurred. What followed was a period where the Soviet secret police, under Stalin's directives, executed mass purges targeting a vast array of individuals, ranging from party members to military leaders.
Suspected dissenters were arrested, and many were either sent to Gulag labor camps or executed. This period became known as the Great Purge, signifying a brutal and intense crackdown to solidify Stalin's control over the Soviet Union and to eliminate potential threats to his power.