The event caused Ivan to be less terrible for a short period of time was his mother's death.
Answer: Option B
Explanation:
Ivan IV Vasilyevich was a Moscow prince, and in 1547, he became the earliest Russian tsar. He was an dictatorial ruler and during his reign the people suffered greatly because he was responsible for the massacre in Novgorod.
He killed both his elder son and unborn grandson, which led to political instability in the empire. Ivan's childhood was full of struggles when his mother died at the age of eight and spent his childhood as a peasant, fighting between rival aristocrats.