Which of these techniques originated in the realist era? a. the trend of using heroic characters b. the use of dialect in speech c. the trend of employing tragic themes d. the use of imaginary settings

I believe the correct answer is B. the use of dialect in speech.
A is incorrect as heroic characters have existed for a very long time (just remember Beowulf); C is incorrect as tragedy was invented back in ancient Greece, which was a looong time before the realist era; D is incorrect because the use of imaginary settings is a characteristic of the romantic era, which preceded the realist era. This leaves us with B, which is evident if you take a look at Huckleberry Finn, for example, which is a good example of Realism.

What do you mean by this?