The most appropriate antonym for "hospitality" is "coldness." Hospitality refers to the warm and friendly reception and treatment of guests, so "coldness," which implies a lack of warmth or friendliness, serves as the opposite. The other options— "complaint" (a statement expressing dissatisfaction or annoyance), "cordiality" (warmth and friendliness), and "wrathful" (full of or characterized by intense anger)— do not convey the opposite meaning of "hospitality" in this context.

The most appropriate antonym for "trivial" in the given sentence is "serious." "Trivial" refers to something of little importance or significance, so the opposite would be something of great importance or seriousness. The other options— "underrated" (underestimated), "kind" (having a gentle nature), and "problematic" (posing a problem or difficulty)— do not convey the opposite meaning of "trivial" in this context.