Step 1: Understanding the Concept:
The question requires identifying key characteristics of Postmodernism, a significant literary and cultural movement of the mid-20th century.
Step 2: Detailed Explanation:
Analyzing each statement:
\[\begin{array}{rl} \bullet & \text{(A) Focus on classical themes of heroism: Incorrect. Postmodernism rejects traditional heroism and classical ideals, often featuring anti-heroes and questioning heroic narratives. } \\ \bullet & \text{(B) Promotes the idea of multiple perspectives: Correct. Postmodernism rejects a single objective truth, embracing relativism, subjectivity, and multiple, often conflicting, perspectives. } \\ \bullet & \text{(C) Challenges grand narratives: Correct. Postmodernism, as articulated by Jean-François Lyotard, questions "incredulity toward metanarratives" or grand narratives (e.g., the Enlightenment's Progress, or Marxist history). } \\ \bullet & \text{(D) Focus on metafiction and intertextuality: Correct. Postmodern literature is self-aware, drawing attention to its artistic status (metafiction) and its relationship to other texts (intertextuality). } \\ \end{array}\]Therefore, options (B), (C), and (D) represent correct characteristics.
Step 3: Final Answer:
The correct option is (D).