D. that false appearances are pervasive in society
The poem is describing how the people are wearing false smiles while inside they cry. The first line says, "We wear the mask that grins and lies". By not being specific about who is wearing the mask and using the collective pronoun "We", Dunbar is including everyone in his description of who wears the mask. Options A, B, and C are all wrong because there is no feeling or bravery or sympathy, and no indication of torture.