Answer:
Conservative mode of replication
Step-by-step explanation:
Meselson and Stahl performed the experiment to test how the DNA molecule replicates in the organisms.
He performed the experiment on E. coli by culturing them in N¹⁵ isotope and then transferring them to N¹⁴ isotope.
When he analysed the DNA sample through density centrifugation he found that in Generation One or one round of replication the intermediate band between the N¹⁴ isotope (lighter) and N¹⁵ isotope (heavier) isotopes.
This result showed that now the DNA contains both forms of isotope that is it is in favour of the semi-conservative and dispersive mode of replication but not conservative mode pf replication.
Thus, Conservative mode of replication is the correct answer.