What created the main pressure for Tsar Nicholas II's abdication?

Correct answer: From mass movement, soldiers' mutiny and political crisis

The governing historical concept is the February Revolution as a combined political, social and military crisis. In Petrograd, workers’ protests were intensified by food shortages, especially bread queues, and the war had already produced enormous hardship and dissatisfaction. The decisive development was that soldiers refused to continue repressing demonstrators and many joined the uprising. At the same time, the Tsar lost political support and the Duma became involved in the crisis. These pressures together made continued autocratic rule impossible and led Nicholas II to abdicate. Foreign trade growth, a church-tax change or a peasant festival cannot explain this collapse. Thus option A is correct.