Final answer:
Rasputin became a trusted advisor to Tsarina Alexandra due to his ability to relieve her son's hemophilia.
Step-by-step explanation:
Rasputin became a trusted advisor to Tsarina Alexandra due to his ability to relieve the suffering of her young son Alexei, who had hemophilia. Rasputin, a wandering monk and faith healer, was able to stop Alexei's bleeding, which led the Tsarina to believe that he had been sent by God to protect the royal family. Despite being illiterate and coming from a peasant background, Rasputin quickly gained influence and became a powerful figure in the Tsar's family.