Final answer:
The Bolsheviks believed Czar Nicholas II was a threat to the Russian Revolution and saw his execution as a way to eliminate that threat. They also sought revenge for his oppressive rule and wanted to send a message to the monarchy.
Step-by-step explanation:
The Bolsheviks believed he was a threat to the Russian Revolution and saw his execution as a way to eliminate that threat. The assassination of Czar Nicholas II was motivated by the Bolsheviks' perception that he posed a danger to the success of the Russian Revolution. By killing him and his family, they aimed to eliminate the potential for a counter-revolutionary movement and symbolize the end of the old regime. Additionally, the Bolsheviks sought revenge for Nicholas II's oppressive rule and wanted to send a message to the monarchy.