Step 1: Concept
Plant classification systems: APG IV (Angiosperm Phylogeny Group IV).
Step 2: Meaning
APG IV classifies flowering plants based on shared evolutionary (phylogenetic) relationships derived from molecular data.
Step 3: Analysis
APG IV uses DNA sequence data (molecular characteristics), particularly from chloroplast and nuclear genes, to establish phylogenetic relationships. This contrasts with earlier systems based on morphology or anatomy.
Step 4: Conclusion
APG IV is based on molecular characteristics.
Final Answer: (C)