Correct Answer: metaphase

Solution : The correct option is metaphase.

The morphology of chromosomes is best studied during metaphase during cell division because the chromosomes are most compacted, and visible under a microscope at that time. Metaphase is a stage of mitosis (cell division) in which the chromosomes align along the equatorial plane of the cell, making them identifiable, and visible. Because the condensed chromosomes are tightly coiled, and organised, scientists can analyse their structure, quantity, size, and any abnormalities with more precision than in other periods of the cell cycle.