Answer :
Final answer:
The leaders of the provisional government lost support due to their decision to continue the war effort despite its unpopularity.
Explanation:
The decision that the leaders of the provisional government took that cost them the support of a significant part of the Russian people was continuing the war effort despite its unpopularity.
This decision led to dissatisfaction among the people as the war brought about hardships and casualties, creating unrest and disapproval towards the government.
Additionally, as the Provisional government failed to bring order and address the needs of the population, the support shifted towards alternative power structures like the Soviets, further diminishing the government's backing.
Learn more about Provisional Government's Decision Causing Dissatisfaction here:
https://brainly.com/question/31718368