What was tsarina alexandra’s biggest mistake after she took over the leadership of the russian government?

Tsarina Alexandra's biggest mistake after she took over the leadership of the Russian government while her husband Nicholas II was on a battlefield was putting too much trust and confidence to Rasputin's decisions which regard to running the country. People of Russia no longer trust the royal family since then. Hope this answer helps.

What research did you learn from?

The answer to the question is a.