The correct answer is B) since he felt insecure about educated intellectuals he had to avoid presenting a logical argument.
The difficult task did Stalin most likely face when he tried to use logos in his speech was "since he felt insecure about educated intellectuals he had to avoid presenting a logical argument."
That is why he better used Pathos in his speech, the appeal to the emotions to convince people. He found difficult to use Ethos also because he had to make himself seem trustworthy to his people despite he had starved and tortured many Soviets.
Let's remember what Ethos is. Ethos is the ethical appeal in the discourse. You use Ethos when you want to convince an audience through your reputation, credibility or character.
The other two elements are Pathos, the use of emotions to appeal to an audience, and Logos, the use of logic or reason to appeal to an audience.
