• Double-Strand Break Repair (DSBR) Model of Recombination (Szostak et al., 1983):
• Two Holliday Junctions Formed: Repair of a double-strand DNA break involves $5'\rightarrow 3'$ resection, strand invasion by $3'$ single-stranded overhangs, DNA synthesis, and ligation, generating an intermediate with two Holliday junctions.
• Four Topologically Equivalent Ways of Resolution: Each of the two Holliday junctions can be independently cleaved by resolvase enzymes in either the horizontal or vertical plane ($2 \times 2 = 4$ possible cleavage combinations). Cleavage of both junctions in the same plane produces non-crossover (gene conversion) products, whereas cleavage in opposite planes produces crossover (recombinant) products.
• Incorrect Statement: Option 2 asserts that Holliday junctions can be resolved by only "two topologically equivalent ways", which is biologically incorrect because four distinct topological resolution combinations exist.
• Conclusion: Option 2 is the statement that is NOT correct.

Correct option: (2) Holliday Junctions can be resolved by two topologically equivalent ways